faire contre mauvaise fortune bon cœur

You use it as a full verb phrase. You conjugate faire to match the subject. If you are talking about yourself, say je fais contre mauvaise fortune bon cœur. It sounds sophisticated. It shows you are in control of your emotions. You can use it to describe your own resilience. You can also use it to praise someone else's strength. It is a very versatile idiom for C1 speakers.

Use it when plans fall through. Use it at work when a project is canceled. It is perfect for social setbacks. Maybe your favorite restaurant is closed. You tell your date, "Let's go to the bistro next door instead." You are being a good sport. It works well in emails to show you are not discouraged. It is great for personal stories about overcoming obstacles. It makes you sound mature and composed.

Do not use it for massive tragedies. It is too light for a funeral or a major disaster. It is for 'fortune', which usually implies luck or circumstances. Avoid using it if you are actually angry. If you say it with a scowl, the irony might be too heavy. Do not use it in very short slangy texts. It is a bit too elegant for a 'u up?' style message. Keep it for when you want to sound articulate.

This phrase dates back to the 16th century. It comes from a time when 'fortune' was seen as a fickle goddess. People believed you couldn't control fate, only your reaction to it. The 'heart' represents your courage and spirit. Stoicism is a big part of French intellectual history. This phrase is a perfect tiny piece of that philosophy. It reflects the French value of 'dignity' in the face of inconvenience.

You might hear people just say bon cœur in some contexts, but the full phrase is the standard. Sometimes people swap 'fortune' for 'chance' in casual speech, but stick to the original. It is so established that even a partial reference works. If you say, "Il faut faire bon cœur," people will know exactly what you mean. It is a classic that never goes out of style.