Dreaming is your bodies way of processing what you have done during that day, or the previous few days. Your thoughts that you have had, things that you have done, said, listened to. It is your brains way of storing things in your long and short term memory, and kicking out the stuff it doesn't need, so it can save important room for the stuff that you do need. They don't really "mean" anything other than you have obviously been thinking about the things in your dream. Our brains work in funny ways, and will skew thoughts sometimes. I am doing neuroanatomy at the moment, and we have been studying dreams, and they have done looootttts of experiments on dreaming patients, and that is basically the answer they came up with.