noun
formative experience; primal experience
Refers to a deeply influential experience, often from childhood or youth, that shapes one's values, personality, or life direction.
彼の音楽の原体験は、幼い頃に聴いたクラシックだった。
His formative musical experience was the classical music he heard as a child.
この小説
This novel is based on the author's primal experience of war.