The true sign of intelligence is not knowledge but imagination.
Insanity: doing the same thing over and over again and expecting different results.
The difference between stupidity and genius is that genius has its limits.
A person who never made a mistake never tried anything new.
We cannot solve our problems with the same thinking we used when we created them.
No problem can be solved from the same level of consciousness that created it.
If you can't explain it simply, you don't understand it well enough.
Any man who reads too much and uses his own brain too little falls into lazy habits of thinking.
When you are courting a nice girl an hour seems like a second. When you sit on a red-hot cinder a second seems like an hour. That's relativity.
A question that sometimes drives me hazy: am I or are the others crazy?