像所有的成人一样，幼儿也有他独立的人格。

The most important thing in mathematics is to understand the concepts, not just to memorize the formulas.

And what I noted, since the really big ideas carry 95 percent of the freight, it wasn’t at all that hard for me to pick up all the big ideas and all the big disciplines and make them a standard part of my mental routines. Once you have the ideas, of course, they are no good if you don’t practice. You don’t practice, you lose it.

Continuous learning is the only way to cope with rapid technological changes.