for me it's typically obsession with certain subjects. When I was young it was the bible, and jesus. Computers, Qabalah, Steem.... These obsessions tend to have a certain life to them. I get focused on one thing, obsess about it, learn everything possible, and then my mind finds something else to be obsessed with once I see the shortcomings.
I've watched every episode of adventure time many times, and I used to go to bed to the same movie every night... there are movies I've seen hundreds of times... but I've never watched the same thing over and over and over....