Then when I moved room the toilet was black with filth and I ended up spending >3 hours scrubbing it until me and my new roommate were comfortable even going near it, he was stuck cleaning other parts of the room in trade for me doing the toilet.

Thanks for reminding me I had (have, but we are basically polar opposites and thus only really interact during the rare times when our entire mutual friend group specifically hangs out) a friend who was 24, in a top 10 law school, and shared a 2br/2ba apartment with another friend. This man was the most disgusting person I've ever met and I am self-aware enough to admit that I am a pretty messy person (in the 'sometimes has piles of clothes on my floor' sense). But this was post-college levels of filth I've still yet to see topped.

Our entire friend group would hang out at their apartment pretty often and would tell new people "hey, don't use X's bathroom its traumatizing" because it was quite literally also black with filth & mold. To make matters worse though, the dude would use the SAME ceramic coffee mug daily but also leave it out with coffee in it - never once cleaned it. He'd at best dump it out and run it under the tap for a second, but was adamant that the heat of the new coffee would sterilize any bacteria/mold. Was generally the same way with dishes - to the point where his roommate (whose girlfriend is one of my very close friends) literally bought an entire separate set of dishes/utensils/cookware because anytime his girlfriend was over and they wanted to cook, there'd be nothing remotely clean.

Well - one day I went over to hang out and he wasn't at the apartment. "Go look in his bathroom, you'll see something really funny" His roommate's girlfriend tells me.

Behold.

That was the completed result after he'd spent like 2 hours cleaning the toilet with one of the brand new toilet brushes he'd bought a 2-pack of. Note how low the water level is in the toilet. Apparently he'd literally clogged it with accumulated filth in the bowl (it was historically never that clean as shown in the video and looked more like the entire inside of the toilet bowl had succumbed to rust as you can see by the dark upper crust around the bowl lmao) and when he called the apartment complex's maintenance out to take a look - the maintenance guy was apparently so disgusted that he (rightfully) demanded that since it was still somewhat able to flush it be cleaned before he did any work on it, which prompted him to go out and purchase the first toilet brush he had ever presumably used.

Anyways he's a lawyer now at a pretty notable firm in DC (with a girlfriend who presumably does all the housework...) and makes like 5x as much money I do in a single year