As someone who can never read more than one book at a time, I'm always fascinated and also confused when I see accounts on here that are reading 3 or more books at once

Sometimes I'll see a few accounts have around 10 books they are reading at once and it makes me wonder if that's true, and if it is, how?? To me, it sounds like it would be hard to remember what's happening in each book

I hope this is an ok question to ask on here, I'm just curious to know more about why people do it!