All-nighters, my toxic habit in undergrad

At first, I was worried about being a student again, mostly because I did not handle stress well the last time I was one. When I was an undergrad, my most toxic habit was to pull all-nighters, sometimes consecutively. I have vague memories of being awake for more than two days. If I didn’t pull an all-nighter, I would probably only sleep 2-3 hours the night before an exam and then wake up at 5:00 am to study.