I was one of those people lol. When I was in pharmacy school, I would knock on my friends doors to go out for the night (nothing crazy- there was this one huge nice bar that gave ladies free champagne and strawberries Thursday nights) and they would say they couldn't bc they were studying for medicinal chemistry. I would remind them the test was in 3 weeks but that's their study schedule, not mine. I was never once spotted at the library(it smelt funny and I can't be quiet and and not joke around for that long). It was surprising on graduation day that I had several bling cords around my neck, one being honors. No one ever suspected.
Being social and going out isn't necessarily wrong if you know yourself and what you need to prioritize, as well as the study habits that work for you.
Edit: and yeah, there are know it all everywhere. I would just smile and nod, knowing all they do is study and talk about how stupid they think so and so is, but they look foolishly pretentious and now they work retail pharmacy, which is the equivalent to eternal hell.