当儿童还没有发展起控制能力的时候，让儿童想干什么就干什么是与自由观念相违背的。

I don't believe in over-diversification. I prefer to focus on a few good ideas.

The only person you should try to be better than is the person you were yesterday.

反射是神经活动最简单和最常见的形式。