The only real valuable thing is intuition. The intellect has little to do on the road to discovery

If you can't explain what you are doing to a nine-year-old, then either you still don't understand it very well, or it's not all that worthwile in the first place.

artificial intellegance is no match for natural stupidity

I was originally supposed to become an engineer but the thought of having to expend my creative energy on things that make practical everyday life even more refined, with a loathsome capital gain as the goal, was unbearable to me.

If you cannot explain it simply, you do not understand it enough.

The ordinary adult never gives a thought to space-time problems ... I, on the contrary, developed so slowly that I did not begin to wonder about space and time until I was an adult. I then delved more deeply into the problem than any other adult or child would have done.

A little knowledge is a dangerous thing. So is a lot.