Yanamino小时了了，大未必佳
xiǎo shí liǎo liǎo , dà wèi bì jiāxiaoshiliaoliao,daweibijia
- being bright at an early age does not necessarily bring success upon growing up (proverb)
Data from JMdict, KANJIDIC2 (EDRDG), KanjiVG, CC-CEDICT and Make Me a Hanzi. Sources and licences