In theory, there is no difference between theory and practice. But in practice, there is. (Yogi Berra)

All are lunatics, but he who can analyze his delusion is called a philosopher. (Ambrose Bierce)

The fundamental cause of trouble in the world is that the stupid are cocksure while the intelligent are full of doubt. (Bertrand Russell)

I have not failed. I’ve just found 10,000 ways that won’t work. (Thomas Alva Edison)