Adversity makes a man wise, not rich.

Meaning: Hardship teaches wisdom even when it never fills your pockets.

Origin: Recorded in A Dictionary of English Proverbs and Proverbial Phrases, an undated collection published in London by Whittaker & Co. around 1880 and credited to Thomas Preston. Its earlier history hasn't been traced.

Equivalents in French, Spanish, Japanese, German, Dutch, and 2 more languages

French: Vent au visage rend un homme sage (literally: Wind in the face makes a man wise)
Spanish: De los escarmentados nacen los avisados (literally: From those who have learned the hard way come the wary)
Japanese: 艱難汝を玉にす (Kannan nanji o tama ni su) (literally: Hardship polishes you into a jewel)
German: Durch Schaden wird man klug (literally: Through harm one becomes wise)
Dutch: Door schade en schande wordt men wijs (literally: Through loss and shame one grows wise)
Russian: За битого двух небитых дают (Za bitogo dvukh nebitykh dayut) (literally: For one who's been beaten, you'd get two who haven't)
Chinese: 吃一堑，长一智 (Chī yí qiàn, zhǎng yí zhì) (literally: Fall into a ditch, gain in wit)