[dkuznetsov]

Something similar, albeit not as severe happened to me, also as a result of a bicycle-related head injury.

I was on my way back home in Montreal. I consider English to be my second language. I have two mother tongues - Ukrainian and Russian. And, due to living in Montreal, I had passable French. So I lost ability to speak or understand French for a few days. After I re-gained it, it became visibly worse. Also I had short term amnesia - didn't know who I was, where I lived or where I was going from/to. Luckily, most of the things came back to me within the next few hours or days.

Brain is a bizarre device...