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

If you can’t get rid of the skeleton in your closet, you’d best teach it to dance. (George Bernard Shaw)

Each problem that I solved became a rule which served afterwards to solve other problems. (Rene Descartes, Discours de la Methode)

His ignorance is encyclopedic (Abba Eban)