In my experience, i have found that dreams are based on real life. Most of what i have done and/or seen during the day normally relate to me in my dreams. Obviously in the dream world the reality is changed slightly, however i have realized for myself that my thoughts that are suppressed during the day, usually come up in my dreams. Its as though my mind let's out everything in my dreams, of which i would have kept to myself in waking life. That's just my experience though.