In theory, I know the solution to every puzzle in the Hitchhiker's game. In practice, I've solved every one of them that you can solve while missing others (there's a gate right at the end of the game you have to have all of the items you can possibly get to get past)... but I have never strung all these solutions together into one winning game, despite several attempts.
It's a nasty little game, really.
I guess if I were doing it again nowadays I'd be going for a tool-assisted... umm... speedrun isn't really right here, so win-at-all-run.