痛定思痛

痛定思痛 [tòng dìng sī tòng]

1. ■ recall past pain -- as a warning for the future; bring home the lessons painfully learned; draw a lesson from a bitter experience; recall a painful experience; recall the past with pangs in the heart; reflect [ponder] sufferings and pains after they are gone; take one's painful experience to heart; think over the reason after this bitter lesson