I've always considered myself pretty fluent in English, though it's not my native language (obviously).

So, you may ask, why am I asking you this? Well, I've seen many people on language-learning websites claiming to fluent in English (and even filling their language fluency bar all the way), but when I'd check out their profile, I'd see they speak very broken English . . . which got me thinking, am I like them? Am I really overestimating my fluency? I'd like to know your opinions, and please be completely honest.Thanks =)