过犹不及
Overdone is worse than underdone.
The archer who overshoots misses as well as he that falls short.
In excess nectar poisons.
He that makes a thing too fine breaks it.

eg：You must not push your way too hard in the world as overdone is worse than underdone.

中英俚语俗语来源：论语·先进：“过犹不及。”

同义词：失之过甚 Carry too far.
反义词：聊胜于无 A little is better than none.