Anything: Series, video game, book, food, old toy from childhood, service, etc. Also, any series which you wish did not end, etc.
I imagine Bertram Gilfoyle is the adult that Bill Haverchuck grew up to be
I actually know Martin in real life and worked with him for almost a year and he’s almost exactly like his Guilfoyle character. He probably was Bill as a young person lol. The only difference is he’s super sweet but still has that dead pan sense of fuck you humor.