When BEN was younger, he wanted to make cheese for a living. He died before he could put this dream into action, sadly, but it all turned out in the end as Slender somehow caught wind of this dream of his (god knows how, slender just knows shit like that) and got him a fully-functioning cheese making room for his birthday. No joke, there is literally a room in the mansion with the plaque "BEN's Cheese-Making Room" above it.
(I love cheese. Feta, cheddar, Welsh cheddar- yum.
BONUS: The cheese BEN made at first was pretty shit (he didn't have any experience, cut him some slack) but everyone choked it down because nobody could bear to shatter the excited look on his face. (The videogame glitch was 11ish here. (Yes, ghosts age. I've another Headcannon on it somewhere that you'd know about if you were reading this shit in order which I hope all you little shits are)
EXTRA BONUS: BEN eventually mastered the art of making cheese, and now there has been bloodshed over trying to get the last piece. (This happens a lot... Look, it's a family of serial killers, I'd be concerned if there wasn't bloodshed.)
EXTRA EXTRS BONUS: You can find BEN's cheese at Sally's tea parties. Admittedly, cheese doesn't really fit in with a traditional British tea party, but Sally says quote-on-quote: "it's too good not to include." (I've just noticed I only do this "bonus" thing with the BEN headcannons. Huh. Strange.)