awareness of things around one; ability to understand what is going on around oneself; judgment; judgement; discretion
物心ついた頃から音楽が好きだった。
I have loved music since I became aware of things around me.
物心がつく前の記憶はほとんどない。
I have almost no memories from before I was aware of things around me.
子供が物心つく時期は親の影響を最も受けやすい。
The period when children become aware of their surroundings is when they are most influenced by their parents.