Traumatic experiences with immature students at university

I am in my 2nd year of university. Far from my expectation that people would be mature, most people I met during my time turned out to be the exact opposite. A few of those have said or done some absolutely hideous things which I still cannot get over.
In my first year, there was a girl who lived in the same corridor as me who disturbed me enormously with the various things she said and did. She would actually write pornographic scenarios about people in the corridor (most of them targeting me) and in general because of what she was saying was creepy and disgusting.
She was friends with another girl who kept making extremely offensive and explicit remarks in my direction (and then was saying I had no social skill) and had an issue with near-nonstop swearing as well.
This year, however, I met someone of absolutely unparalleled depravity. This person is just gross- one time, she was trying to convince a group of people that an Egyptian obelisk points up because the male reproductive organ points up. Later, this escalated into (I suspect, intentionally) ruining my sleep by stomping right above my room and being loud in the kitchen, which caused horrific insomnia which I still cannot get over, because I was afraid of sleeping and ended up taking 2 exams in a sleep-deprived state because of her (which I feel went shockingly well considering how I felt)
Is this behaviour common at university? These people are now 20 and 21, I am 22. I keep on encountering-and getting traumatised by- such people, no matter to what accommodation I move. Maybe I expected too much because of the behaviour of a mature 30-year old PhD student I am friends with.

I am in my 2nd year of university. Far from my expectation that people would be mature, most people I met during my time turned out to be the exact opposite. A few of those have said or done some absolutely hideous things which I still cannot get over.
In my first year, there was a girl who lived in the same corridor as me who disturbed me enormously with the various things she said and did. She would actually write pornographic scenarios about people in the corridor (most of them targeting me) and in general because of what she was saying was creepy and disgusting.
She was friends with another girl who kept making extremely offensive and explicit remarks in my direction (and then was saying I had no social skill) and had an issue with near-nonstop swearing as well.
This year, however, I met someone of absolutely unparalleled depravity. This person is just gross- one time, she was trying to convince a group of people that an Egyptian obelisk points up because the male reproductive organ points up. Later, this escalated into (I suspect, intentionally) ruining my sleep by stomping right above my room and being loud in the kitchen, which caused horrific insomnia which I still cannot get over, because I was afraid of sleeping and ended up taking 2 exams in a sleep-deprived state because of her (which I feel went shockingly well considering how I felt)
Is this behaviour common at university? These people are now 20 and 21, I am 22. I keep on encountering-and getting traumatised by- such people, no matter to what accommodation I move. Maybe I expected too much because of the behaviour of a mature 30-year old PhD student I am friends with.

Normal I'm afraid. My uni was a total joke and at least half the people there would have been better off doing an apprenticeship or finding a basic job. They weren't remotely intelligent and regarded uni as a non-stop party or holiday, many were on drugs a lot of the time thinking they were cool rock stars or movie stars or something. For a lot of people uni was just about partying, going to raves and clubbing, and trying to get laid and really nothing else. Most seemed more interested in bands, instagram and the latest trainers from adidas than studying. There were people who rarely turned up to classes and just copied essays from other people and somehow passed, which wasn't that difficult as the professors told us all the exam questions in advance. There was a snobby competitive atmosphere with rich kids from posh families looking down on everyone else and making sarcastic comments about people's accents. Even now, there are people I would love to throw a pint of beer over if I see them again. And this, apparently was a top 10 Russel Group institution. It was dreadful really.

I am in my 2nd year of university. Far from my expectation that people would be mature, most people I met during my time turned out to be the exact opposite. A few of those have said or done some absolutely hideous things which I still cannot get over.
In my first year, there was a girl who lived in the same corridor as me who disturbed me enormously with the various things she said and did. She would actually write pornographic scenarios about people in the corridor (most of them targeting me) and in general because of what she was saying was creepy and disgusting.
She was friends with another girl who kept making extremely offensive and explicit remarks in my direction (and then was saying I had no social skill) and had an issue with near-nonstop swearing as well.
This year, however, I met someone of absolutely unparalleled depravity. This person is just gross- one time, she was trying to convince a group of people that an Egyptian obelisk points up because the male reproductive organ points up. Later, this escalated into (I suspect, intentionally) ruining my sleep by stomping right above my room and being loud in the kitchen, which caused horrific insomnia which I still cannot get over, because I was afraid of sleeping and ended up taking 2 exams in a sleep-deprived state because of her (which I feel went shockingly well considering how I felt)
Is this behaviour common at university? These people are now 20 and 21, I am 22. I keep on encountering-and getting traumatised by- such people, no matter to what accommodation I move. Maybe I expected too much because of the behaviour of a mature 30-year old PhD student I am friends with.

That's hardly "unparalleled depravity"!

They are kids still. Why anyone thinks that age group is mature boggles my mind. One's definition of adult and its relation to age is clearly wrong.

Maybe not to you