Einstein and a colleague were sitting having a coffee chatting about physics.
His colleague suddenly stopped, pulled out a small notebook and wrote a couple of words in it.
Einstein asked "What was that for?"
His colleague replied. "I always carry a small notebook around with me, and then, if ever I have a good idea, I can make a quick note so as not to forget it later. You should try it Albert".
Einstein replied "Oh, I don't need one of those, I've only ever had two good ideas".