Everybody knows that its now or never.

每个人都知道要把握时机。

youdao

Its now or never, never tomorrow, and never next second!

现在就付诸行动，永远不要等到明天，永远不要等到下一秒！

youdao

Every now and then a man's mind is stretched by a new idea or sensation, and never shrinks back to its former dimensions.

每隔一段时间，人的思维就会因新思想或新感受而扩展，并且绝不会缩回到原来的尺寸。

youdao

Zynga grew fast and hard under circumstances that will never exist again, and now its seeing whether or not it can hang onto that growth.

FORBES: Zynga Stock Sinking Along With Facebook -- Is Now The Time to Buy?

Without that rebellion, say those once involved (many of them now respected public figures), Germany would never have confronted its Nazi past or become so open, tolerant and democratic.

ECONOMIST: Charlemagne