Is it normal my coworker is still english?

He's a guy, age 22. Everyone at my work practically drools over his accent and he keeps talking about losing it. He says he came here when he was 15 and despite writing American in school and trying to blend in a bit with kids when he was in HS and even now, he still hasn't lost it but wants to. He says if you're young, you often lose it and he wants to be American because he doesn't like people knowing he's English.

He says he moved here to be with his Aunt because his Mother passed away and he was an only child. His Aunt is American and he's lived here for 7 years now but his accent is exactly the same/just as thick. He doesn't even sound American at all. I think there's maybe one word he says more American than British but that's it. Like, instead of Awwnt, he says Ant like us haha.

is it normal he still sounds English?