Ed Norton's inspiration?
I just happened to be looking at an old X-Files. In the first season, episode 24 was called "Roland" (1994), about a retarded janitor in some propulsion plant. He was played by Zeljko Ivanek. He (Roland) moves and acts exactly like "Brian", the "character" Jack Teller (played by Norton) invented to get a job in the customs house.
Could this have been where he first came up with the persona?