In Ireland we have the phenomenon known as a "Spoiled Priest." Unlike a spoiled child, this does not refer to a Priest throwing a temper tantrum.

I think, generally speaking, that children have a knack for picking up curse words. Having said that, my brother and I (although admittedly, it was I who displayed a higher level of fluency) took to cursing like frogs take to jumping. Mind you, we received excellent tutoring along the way.