why do people at college act like THAT???

im a freshman, and since i first stepped a foot inside campus people acyed like you cant make mistakes anymore?? i have a friend that moved from another college to mine, she was almost a year above me but ended up being downgraded to a freshman since she technically hadnt passed the year due to her dropping from that school earlier than she should, anyway, shes now my friend. what irks me is that she gets so annoyed when snother freshman doesnt know about the topic being discussed on the lesson even if its the first time we talk about it (¬_¬ꐦ) like?? excuse me for not knowing something that you already do because theyve teached you before??? and its not just her, its also sophomolres and juniors (not seniors tho, theyre nice), its like we have to enter college knowing EVERYTHING or we are a failure?? but also, if we DO know a topic that hasnt been discussed we get called "pretentious" (≖_≖ ) theyre not happy about anything and it contantly feels like i have to compete against people that i dont know and have more experience than i do just because they somehow see me as a threat?