A proverb meaning you cannot truly understand another's pain until you experience it yourself; an admonition to empathize by imagining or undergoing similar hardship.
教師は生徒に対して、我が身をつねって人の痛さを知れと、もっと思いやりを持つように言った。
The teacher told the students, "pinch yourself and know others' pain," urging them to be more compassionate.
彼女はまず自分で苦労してみるべきだ。『我が身をつねって人の痛さを知れ』という言葉が当てはまる。
She should try struggling herself first. The saying 'you must experience it yourself to know another's pain' applies.
ボランティア活動で初めて、我が身をつねって人の痛さを知れという教えの意味が分かった。
Only after volunteering did I understand the meaning of 'experience it yourself to know others' pain.'