This may seem like a dumb question. I bought my first guitar yesterday, from a small used shop downtown. I'd never really played before, but the guy at the store tuned it up for me. I asked him why there was only five strings and he acted as though I was the biggest idiot he'd ever met. I managed to get this guitar for quite a good price, but I've been having problems trying to play it. I'm not really convinced that he tuned it properly. Then a friend told me that guitars are only supposed to have four strings, so I don't even know what kind of an instrument I purchased. Needless to say, I am quite hurt and humiliated by the whole event. Any advice?