expression
failure is the mother of success
Proverb meaning that failure teaches valuable lessons and leads to eventual success. Often used to encourage someone after a setback.
See also: 失敗は成功のもと (しっぱいはせいこうのもと)
失敗は成功の母だから、落ち込まないでまた挑戦しよう。
Failure is the mother of success, so don't get discouraged and try again.
Variant of the same proverb using もと (source/origin) instead of 母 (mother). Essentially synonymous.
A Japanese proverb likely adapted from a similar English saying. The exact origin is uncertain.