一失足成千古恨
one false move brings everlasting grief;a single slip may cause eternal sorrow; the error of a moment becomes a lifetime regret
一失足成千古恨yī shī zú chénɡ qiān ɡǔ hèn
比喻一旦犯了严重错误或堕落,就会成为无法挽回的遗憾。a single slip may cause lasting sorrow, A trip at one point may make one woeful for life.