Oh- and it's also interesting that you used language as an example of this effect.
I was very definitely trilingual as a toddler-- and I was both verbose and fluent in all three. I am now only monolingual on a good day.
LOL.
On the other hand, in high school, I had two friends whose first language was German, and I had no trouble understanding them when they-- and they both did this-- would inadvertently "insert" German terms into their spoken English when they came up short on vocabulary knowledge.
So I apparently can't dredge it up at will, but my brain has a built-in translator that is still operational and intact, as long as I'm not paying too much attention to the processing step itself.
It works that way for me when I'm overseas/immersed in a language that I know, too. I can verify that because I've had it happen in the real world.
But the point is that in the case of two of those languages, those were languages that I acquired as a baby and toddler-- and have emphatically not studied since, unless you count German/Dutch (and I do).
In fact, with the third language, my elapsed latency was probably 40 years or more before hearing it again from native speakers when traveling (and it is not a language related to much else or common elsewhere). But it was familiar enough that within a few hours, my brain was filling things in.
This is mostly useful when using public transportation and finding one's way around in a strange setting, btw, without offending the locals. It is certainly true that I seem to have a knack for languages-- but I don't think it's extreme, by any means. I know a few people like that, and I'm not one of them.
