Insanity: doing the same thing over and over again and expecting different results.
The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it.
A person who never made a mistake never tried anything new.
Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning.
Any man who can drive safely while kissing a pretty girl is simply not giving the kiss the attention it deserves.
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?
Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.
The difference between stupidity and genius is that genius has its limits.
We cannot solve our problems with the same thinking we used when we created them.
Gravitation is not responsible for people falling in love.
A man should look for what is, and not for what he thinks should be.
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either.
The true sign of intelligence is not knowledge but imagination.
Imagination is more important than knowledge.
Great spirits have always encountered violent opposition from mediocre minds.
If you can't explain it simply, you don't understand it well enough.
Try not to become a man of success, but rather try to become a man of value.