There would be no way for them to gain that knowledge. I could believe that they potentially lost their primary language and spoke a mild amount of other languages that they had picked up by osmosis…
But I am doubtful that they would be able to have a full conversation with a native speaker.
There’s no way the human brain could just conjure up a fully functioning secondary language that the person had no exposure to.
Understanding underlying causes? On Lemmy? Abso-fucking-lutely not!
If you like strudel and Hitler liked strudel, then you’re Nazi by default. That’s just simple logic.