Speaking as someone who is always having brain farts in my daily life, I advise you to never admit to having trouble figuring something out - it's downright undignified.
But I did figure it out eventually. This is just usability feedback on behalf of other newcomers.
I also closed that popup right away - and I'm sure many other do as well - after which the rules page becomes hard to find again (why not link to the rules from the
Terms and rules page, where you'd expect to find them?). Furthermore the popup text doesn't mention the Ratings limitation, so you must still read all the rules to learn about that. Why not use the empty
Help page to inform about such things (as well as any other limitations, like hidden sub-forums)?