In 15 Seconds
- Used to highlight a critical fact that shouldn't be overlooked.
- Very formal and authoritative tone, perfect for speeches and essays.
- Functions as a rhetorical 'verbal highlighter' for your main point.
- Usually followed by a full clause starting with the word 'that'.
Meaning
This phrase is a powerful rhetorical tool used to bring everyone's attention back to a foundational truth or a critical fact. It acts like a spotlight, ensuring that a specific piece of information isn't lost in the noise of a complex discussion. It carries a sense of moral or strategic urgency, suggesting that ignoring this point would be a significant mistake.
Key Examples
3 of 10Giving a keynote speech at a tech conference
We must not forget that technology should serve people, not the other way around.
No debemos olvidar que la tecnología debe servir a las personas, no al revés.
Writing a formal business report on market trends
While profits are up, we must not forget that market volatility remains a high risk.
Aunque los beneficios han aumentado, no debemos olvidar que la volatilidad del mercado sigue siendo un riesgo elevado.
Texting a friend about a party
✗ We must not forget that the party starts at eight. → ✓ Don't forget the party starts at eight.
No debemos olvidar que la fiesta empieza a las ocho. → No olvides que la fiesta empieza a las ocho.
Cultural Background
The phrase is often associated with 'Lest we forget,' a line from Rudyard Kipling's poem 'Recessional,' which is used during Remembrance Sunday to honor fallen soldiers. It carries a weight of national duty. In American political rhetoric, this phrase is a staple of 'Civil Religion.' Presidents often use it to invoke the values of the Founding Fathers or the Civil Rights Movement to unify a divided audience. In the global scientific community, this phrase is used to acknowledge the limitations of a study or to remind peers of a fundamental law of nature that must be respected. In modern tech companies, this phrase is often used to 're-center' a team on the 'User Experience' (UX) when they get too bogged down in technical or financial metrics.
The Power of the Pause
After saying 'We must not forget that,' pause for one second before stating the fact. This builds anticipation and makes the fact sound more important.
Don't Overuse It
If you use this phrase more than once in a short speech, it loses its power and starts to sound repetitive or lecturing.
In 15 Seconds
- Used to highlight a critical fact that shouldn't be overlooked.
- Very formal and authoritative tone, perfect for speeches and essays.
- Functions as a rhetorical 'verbal highlighter' for your main point.
- Usually followed by a full clause starting with the word 'that'.
What It Means
Have you ever noticed how some sentences just feel heavier than others?
We must not forget that is one of those heavy hitters.
It isn't just about memory.
It is about priority and perspective.
When you use this phrase, you aren't asking if someone has amnesia.
You are telling them that a specific fact is too important to ignore.
It is the verbal equivalent of slamming your hand (gently) on the table.
It demands that the audience stops and thinks.
What It Means
Think of this phrase as a "moral anchor."
It pulls a drifting conversation back to the most important point.
It implies that the fact following it is a shared responsibility.
We use must to show necessity.
We use not forget to imply a risk of oversight.
It feels serious, grounded, and very intentional.
If you say this, you are assuming a position of leadership or wisdom.
You are the one keeping the group focused on what matters.
It’s like being the only person in the room who remembers where the map is.
How To Use It
You usually place this phrase at a turning point in your argument.
First, you discuss various details or problems.
Then, you drop We must not forget that to introduce the core truth.
It works best when followed by a full clause (subject + verb).
For example: We must not forget that our customers come first.
Notice how it creates a natural pause before the big reveal.
You can also use it to introduce a historical or ethical context.
It bridges the gap between small talk and big ideas.
It’s a great way to sound like a visionary leader.
Just don't use it to remind someone to take out the trash.
Formality & Register
This is a high-level, formal expression.
You will find it in academic essays, political speeches, and business keynotes.
It is definitely a formal to very formal choice.
In a casual setting, it sounds a bit like you’re giving a sermon.
If you say this to a friend at a bar, they might laugh.
Don't forget is the casual younger brother of this phrase.
Use We must not forget that when you want to sound authoritative.
It belongs on LinkedIn, not in a TikTok comment section.
Unless, of course, you are making a very serious TikTok about history.
It’s the tuxedo of English phrases—perfect for the gala, weird for the gym.
Real-Life Examples
Imagine a CEO speaking at a town hall meeting.
They might say, We must not forget that our people are our greatest asset.
Or think of a documentary narrator describing a historical event.
We must not forget that these changes took decades to achieve.
You see it often in journalism when an editor wants to make a point.
It appears in graduation speeches to inspire young graduates.
Even in intense legal dramas, lawyers use it to sway a jury.
It’s also common in climate change debates or social justice rallies.
It frames the information as an essential truth for all of humanity.
It is the language of big ideas and shared values.
When To Use It
Use it when the stakes are high and the message is vital.
It is perfect for concluding a presentation on a strong note.
Use it when you feel a group is getting distracted by minor details.
It’s great for reminding people of the "why" behind their work.
If you are writing a cover letter for a high-level job, use it.
It shows you have a strategic mindset and understand the big picture.
Use it when you want to evoke emotion or a sense of duty.
It’s an excellent tool for persuasive writing.
When the room is loud, this phrase can help bring silence.
It tells people: "Listen up, this part is for the history books."
When NOT To Use It
Do not use this for trivial, everyday reminders.
✗ We must not forget that we need more milk. (Too dramatic!)
Avoid it in casual texts or DMs with your best friends.
It can come off as patronizing if used in a small, low-stakes argument.
If you use it too often, it loses its power.
It’s like spice; a little goes a long way.
Don't use it if you aren't 100% sure the fact is actually important.
If you follow it with a boring detail, people will feel let down.
It’s a promise of importance—don’t break that promise.
Nobody likes a verbal highlighter that marks the whole page.
Common Mistakes
The most common error is forgetting the word that.
✗ We must not forget our goal is profit.
✓ We must not forget that our goal is profit.
Another mistake is using a simple noun instead of a clause.
✗ We must not forget that the deadline. (This is incomplete!)
✓ We must not forget the deadline. (Simple) or We must not forget that the deadline is Friday.
Some learners confuse it with forget about.
Forget about is more casual and often implies dismissiveness.
We must not forget that is always about paying attention.
Don't use should if you want the full rhetorical weight of must.
Should sounds like a suggestion; must sounds like a command.
Common Variations
If We must not forget that feels too heavy, try Let's keep in mind that.
That version is slightly more collaborative and less intense.
It is important to remember that is a very common professional alternative.
In British English, you might hear One must not forget that for extra formality.
Let us not forget that is a classic, slightly more poetic version.
It's worth noting that is the "lite" version for academic writing.
Lest we forget is a very specific, traditional variant used for memorials.
Each variation changes the volume of your voice.
Pick the one that fits the size of the room you’re in.
Real Conversations
CEO
The merger is complex, but we must not forget that our culture is the priority.Manager
I agree, we need to keep the team focused on our core values.Professor
When studying the Industrial Revolution, we must not forget that it changed family life forever.Student
That’s a great point; I hadn't considered the social impact as much.Job Candidate: I have the technical skills, but we must not forget that I also bring five years of leadership.
Interviewer
That is certainly a valuable addition to your profile.Quick FAQ
Is this phrase too old-fashioned?
Not at all, it is used daily in high-level business and politics.
Can I use it in an email?
Yes, especially if you are writing to a client or a superior about a project.
Is it better than "Remember that"?
Yes, if you want to emphasize importance rather than just memory.
Does it sound aggressive?
It can, so use it sparingly and with a professional tone.
How do I pronounce "must not"?
You can say must not separately for emphasis, or mustn't for a slightly softer feel.
Actually, in this specific phrase, we almost always keep them separate.
Usage Notes
This phrase is most effective when used sparingly in professional or formal contexts. Ensure it is followed by a complete clause (Subject + Verb) and avoid using it for trivial matters to maintain its rhetorical power.
The Power of the Pause
After saying 'We must not forget that,' pause for one second before stating the fact. This builds anticipation and makes the fact sound more important.
Don't Overuse It
If you use this phrase more than once in a short speech, it loses its power and starts to sound repetitive or lecturing.
The 'We' is Key
Using 'We' instead of 'You' makes the reminder feel like a shared value rather than a criticism of the listener.
Examples
10We must not forget that technology should serve people, not the other way around.
No debemos olvidar que la tecnología debe servir a las personas, no al revés.
Here it sets a moral tone for the entire presentation.
While profits are up, we must not forget that market volatility remains a high risk.
Aunque los beneficios han aumentado, no debemos olvidar que la volatilidad del mercado sigue siendo un riesgo elevado.
Used to balance good news with a necessary warning.
✗ We must not forget that the party starts at eight. → ✓ Don't forget the party starts at eight.
No debemos olvidar que la fiesta empieza a las ocho. → No olvides que la fiesta empieza a las ocho.
The original is way too formal for a casual text message.
We must not forget that these rights were won through years of struggle.
No debemos olvidar que estos derechos se ganaron tras años de lucha.
Evokes a sense of historical gravity and respect.
Amidst the fun, we must not forget that we are here to support a great cause.
Entre tanta diversión, no debemos olvidar que estamos aquí para apoyar una gran causa.
Adds a touch of seriousness and purpose to a social media post.
We must not forget that we are all on the same team, despite the current pressure.
No debemos olvidar que todos estamos en el mismo equipo, a pesar de la presión actual.
Used to rebuild unity and remind people of their shared goals.
My opponent makes a point, but we must not forget that his policies failed last time.
Mi oponente tiene un punto, pero no debemos olvidar que sus políticas fallaron la última vez.
A classic rhetorical move to discredit an opponent's argument.
✗ We must not forget that to bring a coat. → ✓ We must not forget to bring a coat.
No debemos olvidar que traer un abrigo. → No debemos olvidar traer un abrigo.
You cannot use 'that' followed directly by an infinitive verb.
We must not forget that AI is a tool, and we are the ones who wield it.
No debemos olvidar que la IA es una herramienta, y somos nosotros quienes la manejamos.
Strong, philosophical statement for a modern discussion.
We must not forget that the groom once thought he could cook a five-course meal.
No debemos olvidar que el novio una vez pensó que podía cocinar una cena de cinco platos.
Using a formal phrase for a silly memory creates a funny contrast.
Test Yourself
Complete the sentence with the correct words to create a formal reminder.
We _____ _____ forget _____ the environment needs our protection.
We use 'must not' for strong obligation and 'that' to introduce a fact (clause).
Which sentence uses the phrase in the most natural, formal way?
Choose the best option:
This phrase is best for significant, foundational truths, not minor errands or schedule reminders.
Complete the dialogue using the phrase.
Speaker A: 'The new technology is so fast!' Speaker B: 'Yes, but _____ _____ _____ _____ _____ it also uses a lot of energy.'
Speaker B is introducing a critical fact that balances Speaker A's point.
Match the fact to the most appropriate 'We must not forget that' context.
Fact: 'The company started in a small garage.'
The phrase is used for significant historical or foundational reminders in formal settings.
🎉 Score: /4
Visual Learning Aids
Practice Bank
4 exercisesWe _____ _____ forget _____ the environment needs our protection.
We use 'must not' for strong obligation and 'that' to introduce a fact (clause).
Choose the best option:
This phrase is best for significant, foundational truths, not minor errands or schedule reminders.
Speaker A: 'The new technology is so fast!' Speaker B: 'Yes, but _____ _____ _____ _____ _____ it also uses a lot of energy.'
Speaker B is introducing a critical fact that balances Speaker A's point.
Fact: 'The company started in a small garage.'
The phrase is used for significant historical or foundational reminders in formal settings.
🎉 Score: /4
Video Tutorials
Find video tutorials on YouTube for this phrase.
Frequently Asked Questions
10 questionsIt depends on the email. For a formal report or a serious message to a client, it's great. For a quick note to a close colleague, 'Don't forget that' is better.
Yes, but 'must not' (two words) is much more common in formal writing and speeches because it sounds more emphatic.
'Remember that' is a simple instruction. 'We must not forget that' is a rhetorical statement that implies a moral or logical necessity.
Yes, it is almost always used to start a sentence or a major clause.
Yes! It shows you can think about big-picture values and communicate them clearly.
You can, but 'I must not forget that' sounds like you are talking to yourself. 'We' is used to involve the audience.
Very common, especially in political discourse and news reporting.
It sounds a bit too dramatic for the weather unless the rain is going to ruin a very important event.
Using 'to' instead of 'that' (e.g., 'We must not forget to the meeting').
Use 'Let us not forget that' or 'It is imperative that we do not forget that.'
Related Phrases
Bear in mind that
similarTo remember or consider a piece of information.
Keep in mind that
similarTo remember a fact while doing something else.
Lest we forget
specialized formA very formal way to say 'so that we do not forget.'
It goes without saying that
builds onUsed to introduce a fact that is so obvious it shouldn't need to be said.
