The longer we dwell on our misfortunes, the greater is their power to harm us.

With the fearful strain that is on me night and day, if I did not laugh I should die.

I know that I am intelligent, because I know that I know nothing.

I decided to sell my drawings. However, I didn't want people to buy my drawings because the professor of physics isn't supposed to be able to draw - isn't that wonderful - so I made up a false name.

If you want a love message to be heard, it has got to be sent out. To keep a lamp burning, we have to keep putting oil in it.