Remember how 10 years or so ago there was a middle-eastern fashion for taking American and British people hostage? Quite a few people spent enormous amounts of time chained to walls in small rooms. Some of those hostages wrote books about their experiences and what they did to pass the time. What they liked to do, apparently, was teach each other things. I found it fascinating that no-one was ever taken hostage who didn’t have something of value they could pass on or impart to others.
If you were in a closet in the middle-east for two years with two or three close friends what tutorials would you be able to give? Don’t feel bad if you can’t teach Latin or HTML. Magic tricks, astrobiology. the history of Satanism in Hollywood - anything real that would make closet life more enjoyable is acceptable.