system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does sleep debt/build up work?

If I were to sleep for 24 hours could I then skip the next 3 days of sleep? If so how does it work and if not why does it not work like that?
gpt
The first question to answer is, what is the point of sleep? 

Among some other functions, the primary purpose of sleep is for the brain to enter into a maintenance mode. Think of it as that 2am hard drive defragging that runs when you wouldn't otherwise be on your computer. Instead of space reallocation, however, the brain's process is biochemical and serves to "wash and replenish" the brain's cellular machinery, something that can't happen when the individual is in a waking state. This process is both reactive (meaning it doesn't do any good to do it before there's a mess to clean) and rate limited (which means that it takes X amount of time to achieve Y results). As such, the normal waking/sleeping cycle maintains an equilibrium of building up a mess and cleaning it up. 

You can't bank sleep. That would be similar to cleaning an already clean house for the sake of cleaning it and expecting any mess that you make in the future to come out of the extra work you did. It just doesn't work like that.