You have a good point.

This is also not my personal definition of ''fluency'', but as I have understood it from society and native speakers of different languages. Perhaps my comment was not 100% appropriate to the thread. I just noticed over the years: I could say I'm fluent in english though a native speaker could say they do not agree with that statement. I was commenting under a video in which a deaf person was talking about how people with hearing cannot speak sign language fluently because it is not the language in which they need to communicate their needs 24/7. If that's their definition of ''fluency'' - I get it. And if that's your definition of ''fluency'' - I get it. You seem to have more knowledge of the term so thank you for clearing that up for me.

Conveniently I commented on a YT Video about it today since people wanted to educate a deaf person about their language:

I find there are even few people who can speak their own mother tongue fluently. I am bilingual (english) growing up with the german school system and the internet. However, I often come across a word in both languages that has been lost in the modern world and I therefore didn't know it. I hardly know people who don't have an accent reminiscent of their mother tongue while trying to communicate in another one. Fluent means 100%. You usually only need one language to communicate with those close to you; with whom you speak on a daily basis. However, there are always exceptions as you could see in someones example. (Someone said their mom was fluent since the love of her life was deaf and that's how they communicate therefore she's fluent/"knows" it.)

Even teachers/professors who teach language every day openly admit that they do not know everything about the topic and that their not necessarily 'fluent' in any of them/ ''know'' them. As a native speaker, one simply perceives the language differently. But even as a native speaker, you don't know everything. A lot of our language got lost in history. We're losing some of the fundamentals.

Sorry for the ''rant'' - I'm stoned af and a sensitive being, but I can clearly see that I'm not alone.

To know a language starts with learning it, but I don't think humans can reach the full wisdom, no matter what they want to master. But that's the amazing thing about learning - it never stops and it never gets boring if you're fascinated by it.