Unapologetically Nerdy & Whimsy

Mark is known to have gone to the hospital Numerous Times, to the point where there's an entire twitter account dedicated to counting the days since his previous hospital visit.

Mark has a bit with fans where he claims he's not a masochist, he just wants to know how much his body can take it, and then he'll turn around and willingly put himself through something he knows is going to cause him a lot of pain.

Not including the hospital visits (some more serious than others), Mark has: gotten tased, gotten pepper-sprayed, broken his nose while doing stunts on an aerial hoop, broken his hand after punching it through dry wall, gotten shot with a paintball gun, and probably various others I'm forgetting. These all happened on camera, by the way.

Mark drank his own pee through his brita filter. Twice.

EDIT: Following up the last point, he at one point experimented with a sauna tent by putting in different liquids other than water to steam in. Yes. One of these was his own piss. Pee sauna it was called.

EDIT 2: Mark actually has, what fans like to call, "egos", which are characters that he's portrayed that either he created or that fans created and he then ran away with. These include: himself if he was an egocentric sociopathic murderer; twins stuck in a single body who's whole schtick is to be vague and deliver the most based villain-sounding monologues; Google; a TV entertainer who breaks the fourth wall and is a mass murderer and was seen as the saddest character he probably ever created until Simon came along; a theater kid who loves prison; Indiana Jones; Jim; and more.

Mark actually cannot drink alcohol because his body can't process it correctly. The last time he got drunk, he had to go to a hospital for a heart attack. (This made the choice he made to have Simon drink rubbing alcohol VERY funny to me)

Mark made a tasteful nudes calendar and (I think?) fucked up his hand because he signed thousands of them over the course of a weekend.

Mark made a video announcing that he would create an Only Fans if the podcast he does with his best friends got to number one streaming on Spotify and Apple Podcasts. Needless to say, it became number one in just a few days and he made the Only Fans.

Mark repeatedly has said how badly he wants to be launched into space. Meanwhile, he has massive thalassophobia (fear of the ocean) and also a fear of mannequins.

Mark (affectionately) bullying his fans is actually quite common. Lots of posts said it already, but him mentioning Bloodymary was not a matter of "if" but "when". Because he ALWAYS pokes fun at memes and fandom stuff we create with his work. He also is the BIGGEST enabler of this too. He tells people to pick apart his projects for secrets he put in, and if we get something wrong or we don't find something he'll tease us about it. Fans will then, affectionately, bully him back. Recently, he's had the habit of dying in Subnautica 2 because he forgets to gain more oxygen and like half the comments are making fun of him for this.