I don't dream about my obsessions a lot, but I certainly do. My dreams are generally... weird.
I think I have lucid dreams more than is normal. I also am somewhat... aware in non-lucid dreams, in a way that I sometimes end up doing mathematical calculations or find synonyms in my dreams. The rare times that I'm not aware, I end up believing the dream to be real. (I was actually upset for a week to wake up and find out I wasn't in Australia LOL)
And 90% of the time I have nightmares, instead of waking up, my nightmare just rewinds itself, starts from the beginning, and continues this way until morning. I hate them.