How does it even make sense that we can't become native speakers of other languages?

Language learners know what I'm talking about.<br><br>And I'm sure many of you want to become native speakers of the target language you're learning. Probably to connect with the people on a deeper level.<br><br>And it doesn't matter how old you are.<br><br>I've shaken my head more than once when I heard phrases like "because we already possess a native language our brains are not wired to become native speakers of another language, because it can't change that much and it's too hard to re-wire the whole brains for the other language". And I'm not even being sarcastic here. I've literally heard these words.