why ambitious people turn everything into a competition

I went to UC Berkeley for computer science and I would consider the school hyper-competitive because everyone there wants to be exceptional at everything they do. But I didn't realize until recently, one year out of post-grad, is that it rewires your brain in a way where you can't take anything casually anymore. I don't play for fun, I play to win. Everything I do, like tennis, League of Legends, gaming, no matter what it is, like Catan, I literally have to win. The Berkeley environment kind of put this in my head that everything you do is a chance to prove something. And that's really not how life works. Like sometimes you really should just let loose and play, you know, a sport, a game, for fun. But my mind now just cannot do something bad on purpose if I know that I can be better at it. No matter what the hobby is, I cannot just let a hobby be a hobby and it's a problem, and I know it's a problem, but it's just really hard to get out of this mindset. Like I knew it was bad when I 5v5'd in League with like these random people, right? Like everyone was so nice, but I was the only one flaming. I was the only one calling out like, let's swap teams, like can we team swap, this guy is not doing well. But everyone else was so chill about it, they were just like there to vibe and have fun with their friends and you know, play a damn video game, but I couldn't do it. Yeah, I don't know if anyone else who attended like a competitive school feels like this, but it's not a good thing.