system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If it's possible to build up a sleep debt, is it possible to build up a "sleep credit"? If not, why not?

If I were to sleep more than I needed to during the week, would that enable me to sleep less at the weekend, in the same way that if I sleep too little during the week I have to "catch up"?
gpt
We aren't really sure why, but it doesn't seem that something like that can be done. Think about it like your bladder; you can build up a need to urinate, but you cannot urinate so much that your bladder is more than empty.