mnl I do make sure to get in my sleep, I don't think my body would let me get away with not getting enough. I also have had for the last while a much looser schedule since 2020 and that really helps. I attended classes in person before that and I have to wake up for a 7:30 english class, which was then followed by a 9:00 math class. The math class I took was really boring though, and was at too slow of a pace usually (They went through what seemed like 5 questions for 1 hr and 15 mintues of time). And that usually lead to me falling asleep in the class. I still did well in the class though, as my math skills aren't too lacking.
There was another time where I had an english presentation that was for the same class I mentioned earlier, and I somehow neglected to set my alarm. I work up at about 8:00, panicked, and rushed to class as fast as I could. Luckily, I was scheduled for my presentation for later in the class, and was able to make it in time for things to go smoothly. It was a miricle my body somehow woke me up at 8:00, as if given the chance during that time, my body usually would have slept in at least until 9.