When you sit with a nice girl for two hours, it seems like two minutes; when you sit on a hot stove for two minutes, it seems like two hours. That's relativity.
[Newton wrote to Halley ... that he would not give Hooke any credit] That, alas, is vanity. You find it in so many scientists. You know, it has always hurt me to think that Galileo did not acknowledge the work of Kepler.
What a person thinks on his own without being stimulated by the thoughts and experiences of the other people is even in the best case rather paltry and monotonous.