I don't think you should ever have to apologize for your excitement.

当年的年轻人已变成了花下之尘。

To be human is to be incomplete, always searching.

I don't sing because I'm happy; I'm happy because I sing.

I think that in mathematics, and maybe in life, you have to be willing to be a little bit lost.

Come,my friends,Tis not too late to seek a newer world,For my purpose holds to sail beyond the sunset，And though we are not now that strength which in old days moved earth and heaven,That which we are, we are;-- One equal temper of heroic hearts, Made weak by time and fate, but strong in will. To strive, to seek, to find, and not to yield。

We must build dikes of courage to hold back the flood of fear.