Work as hard and as much as you want to on the things you like to do the best.

I learned very early the difference between knowing the name of something and knowing something.

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.

A scientist is never certain. ... We absolutely must leave room for doubt or there is no progress and there is no learning.

Physicists like to think that all you have to do is say, these are the conditions, now what happens next?

When a Caltech student asked the eminent cosmologist Michael Turner what his "bias" was in favoring one or another particle as a likely candidate to compromise dark matter in the universe, Feynmann snapped, "Why do you want to know his bias? Form your own bias!"

Any schemes - such as 'think of symmetry laws', or 'put the information in mathematical form', or 'guess equations'- are known to everybody now, and they are all tried all the time. When you are stuck, the answer cannot be one of these, because you will have tried these right away...The next scheme, the new discovery, is going to be made in a completely different way.