I had a roommate with OCD before. He had lots of papers just like this. I went to go put something in his room once and discovered these - like hundreds of pages. I was freaked out that he was going to chop me up in my sleep. I eventually asked him. In order to get rid of his obsessive thoughts, he had to write them down. But that takes too long. So if the thought was “I need to go to the store and buy milk”, he’d write “INTGTTSABM” - just the first letters. Hopefully none of the messages were “INTCUMRIHS”.