Never too old to learn, never too late to turn.

亡羊补牢，为时未晚。

New wine in old bottles.

旧瓶装新酒。

No cross, no crown.

不经历风雨，怎么见彩虹。

No garden without its weeds.

没有不长草的园子。

No living man all things can.

世上没有万事通。

No man can do two things at once.

一心不可二用。

No man is born wise or learned.

没有生而知之者。

No man is content.

人心不足蛇吞象。

No man is wise at all times.

聪明一世，糊涂一时。

None are so blind as those who won't see.

视而不见。