I agree its kind of depressing, but you have to sleep in order to spend your time awake doing things. If you didn't sleep you just would be tired all the time and wouldn't have energy to do anything fun or exciting, and you would eventually die from exhaustion.
I mean, if you really get down to the actual amount of sleep we should be getting and how it's split through the day, it's all funny. Before, people wouldn't sleep a full 8 hours. They would split up and sleep two hours here, three hours there. It's funny how times have changed and developed to a "eight hours of recommended sleep" regimen.