I thought it's "jokes on you", with jokes being plural but no, it's just that people often forget the apostrophe. I only figured this out after coming across "the joke was on her". So, there's actually a verb to be in this phrase and it's in the past tense this time.
I used to really love the language and always wanted to learn more. Now, the interest kind of faded. English feels like a mere tool than a whole language with its own cultures. I no longer seek to learn something new.
Reading in English feels boring. Though, I still watch something in English if it's interesting and not too hard that I have to stop to look up words. As a result, my progress has plateaued for quite a while.