Stupid boy!

I may have mentioned before that when I was a kid I fancied myself as a linguist, but a little knowledge can be a dangerous thing.  For example, the German for roof is dach and the German for dog is hund, so dachshund is roof-dog, right?  Never could understand that - why would you have a dog for the roof, did it live up there or what, and in particular why was it bred to be long and thin - where's the advantage in that?   It was years later before I realised that there is another word dachs which is the German for badger, and suddenly all became clear - it's a badger-dog, bred to go down holes and flush the badgers out!