When you're thinking about something that you don't understand, you have a terrible, uncomfortable feeling called confusion... Now, is the confusion's because we're all some kind of apes that are kind of stupid working against this, trying to figure out [how] to put the two sticks together to reach the banana and we can't quite make it... So I always feel stupid. Once in a while, though, the sticks go together on me and I reach the banana.

I have the advantage of having found out how hard it is to get to really know something. How careful you have to be about checking your experiments. How easy it is to make mistakes and fool yourself. I know what it means to know something.

I think a power to do something is of value. Whether the result is a good thing or a bad thing depends on how it is used, but the power is a value.

Ordinarily it would take me about fifteen minutes to get a hallucination going," wrote Feynman, "but on a few occasions, when I smoked some marijuana beforehand, it came very quickly.

If you have any talent, or any occupation that delights you, do it, and do it to the hilt. Don't ask why, or what difficulties you may get into.

What we need is imagination, but imagination in a terrible strait-jacket.

If it disagrees with experiment, it's wrong.