The famous physicist Richard Feynman developed an interesting hobby while stationed on Los Alamos during World War II.
Specifically: he made sport of the combination locks on filing cabinets and safes, to the point that if someone had a document he needed, and they weren’t around, he would go to their office, open their cabinet, then return it once finished - often to the astonishment of his colleagues.
This feat was sufficiently well-known that colleagues would ask him to open others’ cabinets when they weren’t present for documents and so on, to the point that eventually Los Alamos would have a permanent locksmith on staff, who would go on to learn how to open the safes without drilling holes in them.
He also had a habit of taking documents, leaving notes for his colleagues in their place. At first, he signed them with his own name, but later signed the ‘You know who!’ which would cause an incident with base security thinking there was an intruder.