Due to the top secret nature of the work [on the Manhattan Project], Los Alamos was isolated. In Feynman’s own words, “There wasn’t anything to do there”. Bored, he indulged his curiosity by learning to pick the combination locks on cabinets and desks used to secure papers. In one case he found the combination to a locked filing cabinet by trying the numbers a physicist would use (27-18-28 after the base of natural logarithms), and found that the three filing cabinets where a colleague kept a set of research notes all had the same combination. He left a series of notes as a prank, which initially spooked his colleague into thinking a spy or saboteur had gained access to atomic bomb secrets.
That is definitely one way to relieve boredom. What a fucking stud.