When I stay up late, it's usually because I have to finish some work or study for exams. It's quieter at night, so I can concentrate better without any distractions.
I stay up late to chat with friends or family who live far away. Sometimes, I hang out with friends or go out for a late-night snack. It's nice to have some social time.
I work on personal projects or hobbies when I'm up late. I like reading books or learning new things online. It's a good time to focus on what I enjoy.