A contemporary of Socrates, Diogenes puts modern geeks to shame. If you think being holed up in your room playing videogames is intense, consider Diogenes. He spent many of his years living in a barrel outside the temple of Cybele in Athens, formulating philosophies. Alexander the Great is said to have visited Diogenes in his barrel, but from inside the dark barrel the only thing Diogenes could bring himself to say to Alexander was, "Stand out of my sunlight".