The happiest is the person who suffers the least pain; the most miserable who enjoys the least pleasure.
Worrying about them always struck me as about as useful as worrying about getting hit by lightning.
If you aren't fired with enthusiasm, you will be fired with enthusiasm.
The problem is never how to get new, innovative thoughts into your mind, but how to get old ones out. Every mind is a building filled with archaic furniture. Clean out a corner of your mind and creativity will instantly fill it.
Think of life as a terminal illness, because, if you do, you will live it with joy and passion, as it ought to be lived.
He who laughs, lasts!
The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' (I found it!) but 'That's funny ...'