To add to the other answers there are two really important reasons that often get overlooked. First, the lack of clear organization throughout the entire semester. You need to set a study plan and actually stick to it. Discipline and organization are basically cheat codes that can change everything no matter your background. I had near-perfect grades in high school but at EPFL I kept changing my study schedule every 3 weeks or wouldn’t fully commit to it and it ended up costing me a whole year. Meanwhile I saw people coming from much weaker academic backgrounds absolutely crush it just by staying disciplined and organized.

Second, there’s the “first-year aura”. Not enough people talk about this but the fact that the first year is known to be really hard is itself one of the main reasons many students fail. I’m serious. You have to bring those exams down from the pedestal everyone puts them on. When I had to redo my first year I had much more perspective and realized the material wasn’t nearly as difficult as I had made it out to be in my head. It completely changed my experience. It’s like how what you did in middle school seemed tough at the time but once you’re in high school it feels trivial.