I was near native level 5 years ago. I'd additionally watched all the TV shows, the kids shows, read the newspapers and important books, the assigned school poetry. I even memorized the periodic table and read a translation of Feynmans lectures. People honestly thought I was born in Japan.

Five years later, I would struggle to have a conversation about anything consequential. I started learning when I was 19, so I guess too old to have it stick.

Funnily though, I can still read a good amount.