system
A chat on subreddit /r/wallstreetbets
human
Yep. Had to explain exactly that to my 23 year old room mate who's been working for years.

gpt
To be fair, while it definitely should be common knowledge, a paycheck isn't going to show you that info, and most people I know use something like TurboTax, which also doesn't give you info like that, you basically just fill out a questionnaire and you're done. I'm not surprised a lot of younger people don't know how it works.