system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why we get tax returns at the end of the year? Why doesn't the government just tax us the correct amount?

I could be absolutely retarded but it never made sense to me. Is the government just acting like a bank and giving you a fun little bonus at the end of the year? Or is there an actual reason for this?
gpt
TL;DR version: 

* You are taxed based on how much the government thinks you will make in a year.
* You later figure out how much you really made, and thus how much you owed in taxes. This is what people call "doing their taxes."
* If the government taxed you too much, they give some money back. If they didn't tax you enough, then you have to give them some more.