I wouldn't have thought it was useful either, perhaps 10 years ago (although I wouldn't have been thinking about it much at the age of 8 anyway), but Poland joined the EU a few years ago, and there are currently about half a million Polish immigrants living here. There have always been Poles here, as a result of those stationed here in WW2, but this burst of economic immigration has had a major effect on UK & Polish society, so I feel learning it would be pretty useful.
Many do work that is far less skilled than what they were trained to do in Poland, but still pays better, e.g. there is a janitor at my University who was actually a concert pianist, but no one knew until a music lecturer spotted him playing Chopin one night!