zuó​fēi​jīn​shì

to realize one's past mistakes

Senses

昨非今是 zuó​fēi​jīn​shì to realize one's past mistakes

(idiom) realizing that one was wrong in the past and is right now; expressing repentance or a change of heart.

References

same_as 昨非今是/昨非今是 今是昨非/今是昨非
same_as 今是昨非/今是昨非 昨非今是/昨非今是