Albert Einstein

If you can't explain it to a six year old, you don't understand it yourself.

I am enough of an artist to draw freely upon my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world. 

If you want your children to be intelligent, read them fairy tales. If you want them to be more intelligent, read them more fairy tales.

Logic will get you from A to Z; imagination will get you everywhere.

Reality is merely an illusion, albeit a very persistent one.

Any fool can know. The point is to understand.

You never fail until you stop trying.

In the middle of difficulty lies opportunity

Time is an illusion.

Genius is 1% talent and 99% percent hard work...

A ship is always safe at the shore - but that is NOT what it is built for.

Only those who attempt the absurd can achieve the impossible.

You can never solve a problem on the level on which it was created.

Student: Dr. Einstein, Aren't these the same questions as last year's [physics] final exam? 

Dr. Einstein: Yes; But this year the answers are different.

Wisdom is not a product of schooling but of the lifelong attempt to acquire it.