마음에 새기다.

The phrase '마음에 새기다' is composed of '마음' (ma-eum), meaning 'heart' or 'mind', and '새기다' (sae-gi-da), meaning 'to engrave' or 'to carve'. Literally, it translates to 'to engrave in one's heart/mind'. This idiom has a long history in the Korean language, reflecting the cultural emphasis on internalizing experiences and lessons. The concept of engraving something into the heart or mind is a common metaphorical expression across many cultures to denote deep and lasting remembrance or commitment. While a precise 'birth date' for this idiom is difficult to pinpoint, its constituent parts and the underlying conceptual metaphor have been present in Korean language and thought for centuries, likely predating modern written records. It embodies the idea of internalizing a lesson, a promise, or an experience so profoundly that it becomes a part of one's inner being, guiding actions and thoughts. It's often used in contexts of learning important life lessons, remembering advice, or committing to a significant promise. The imagery of engraving suggests permanence and an indelible mark, highlighting the profound impact of what is being remembered.