Why do trolls find trolling funny even if the other person knows they are trolling?

trolls are often people that find other people getting mad for (what they see as) little to no reason funny. Its even more funny to them that the person knows they are getting trolled and is still getting mad at it.

Why wouldn't they? I don't get it...

Because that's how everyone works. They assume they're right/winning/smarter/better than the people around them.

Everyone, troll or not... tends to assume he's "won" any argument, discussion or contest between himself and the people around him. Even blatant losses will be blamed away on things that aren't the person's fault. "Lag". "so-and-so is broken". "You camped me", Etc. It's psychology... there's probably a term for it somewhere. I dunno it off the top of my head.

So this kid decides that he wants to troll. BAM. In his mind, he is already a success at it, because he wants to be. If you lose the game, he'll assume he's won. If you win but he's annoying, he'll call that a win. In his perception he's always going to come out on top. Always. It's not just with trolling... it's the same mentality that makes sportsfans scream at screens that coaches are idiots. Surely THEY would have made the right call and scored points if they were there! People need their egos, and so they put themselves in the winning seat almost ANY time they perceive a conflict... even an imagined one. It's always a moral victory... or an unfair loss... or they didn't care in the first place.

Overcoming this drive is really, REALLY hard.

Long story short, people who troll to see others miserable tend to be sociopaths; these types of people can be classified as mentally ill, much like a sadist (without consent of the other person) is considered mentally ill.

Add in internet anonymity because there is very little to no repercussions for trolling someone, it seems.

Because Riot doesn't care. Until Riot cares we will continue to deal with it.

Sadism. I can't see any other reason how a normal human being likes watching other people suffer for their own entertainment -_-

If you tilt then they win. So dont tilt. Like when a blitz grabs and steals your red buff on your first clear.

often trolling is not the only goal. a lot of trolls are trying to lower their mmr so they can get easier/more fun games. trolling is just something to do while losing so they find anything they can to entertain them.

because it is allowed for a number of games before being slightly punished.

Since Riot doesn't take their game very seriously anymore, why should the player take it seriously and get mad at all the stupid shit Riot does? Trolling is the only fun thing left in this shit game.