How can someone who studies, does homework, and has a job possibly have time to party?

Whenever someone gets good grades, people always seem to comment on how they're worried about how hard they study, and that they should be "living their lives" and "having fun." Imo, I'm living my best life by exceling academically. I think almost everyone has the capacity to do well, they just need to make the right choices everyday, like not partying and not playing video games. I'm not trying to be a good kid or anything like that, it's just that studying, homework, and work are far more important to me than partying, doing drugs, etc. I'm willing to make sacrifices for my academic success. I don't understand why people who party are able to do what they do. How can you have time to study while also partying? I just don't understand.