There are some physicists that, besides having produced exceptional results, can also give a track to follow for future generations. It goes without saying that Enrico Fermi and Richard Feynman are two of these. I am remembering them here because of a couple of quotes to be worthwhile to cite, being complementary each other in some way.
“If we are not alone, where are the others?”
“If we are alone why all this room?”
No answer is known yet to these deep questions. Meanwhile, I think it is wise to read classic papers these two authors produced. When you are tired to see how these guys changed our understanding of the World, you can always turn to “Surely you’re joking, Mr. Feynman” to get a moment of humor.