I have very much experienced this concept this week. I had surgery on Tues. now that is an experience you really have a hard time knowing at times whether you are in reality or a dream. all the medications I have been on make my dreams seem real, and at times I have a hard time telling if I am awake or asleep. There were many times I could hear everyone around me but was unable to respond physically. I am glad to be back in the "real world" even if it is debate able.