Permissions are a great example of they're impossible until they're easy.
The reason you're seeing people say they're easy is because they get permissions. They mindset where linux permissions has clicked for them, and once that happens it actually becomes difficult to remember why things are hard.
The secret is, that's basically everything in this hobby/field. I've spent months trying to understand things that are now trivial to me.
The best thing I can say is Google, talk to friends, play around with them--not just 'this container' but make your own user (or many users), try and do things, and/remove permissions until it changes. Make predictions as you do this and see ahat you can understand and what's still confusing you. Others have recommended chatGPT, and that's fine too as a source to hopefully give you insight--much like a random blog explaining permissions.
Best of luck, the only thing I can say is don't give up for good but definitely don't worry about giving up for the weekend to give yourself a break! You'll get there and one day it'll be easy.