A lucid dream is a dream in which during the course of the dream you realize that "it's just a dream." You don't, however, wake up. You stay asleep and in the REM state. You experience vivid and tangible sensations while fully aware that your "real" body is, in fact, fast asleep and quite still on your bed. You are, in a manner of speaking, in two places at once. It is a most profound experience. It is a scientifically documented human experience (see Stephen LaBerge's books). It is also an extremely rare and difficult experience to attain often and for extensive durations (30 to 45 minutes would be a long time). Most people who have experienced lucidity have only had a few minutes of it. Many only become "semi-lucid" in that they are not fully conscious of their waking mind's intentions, plans, personal information, etc., since they are quickly swept back into the dreaming consciousness after their initial realization by the overwhelmingly vivid sensory experience and their irresitable emotional reactions to it. For the rare individual who has seriously attempted to attain a high level of lucidity and who has had to look the spectre of madness in the face to do it, Castaneda's book is one of only a handful of books that talks about lucid dreaming with any real depth. There are dozens of books on dreaming and even on lucid dreaming specifically which talk about dreaming as something we can harness to serve our waking life's goals; such an approach is naive and in truth dangerous because it trivializes the subject. Castaneda's book is a sobering antidote to these watered-down self-help books. Whether The Art of Dreaming is an actual or fictionalized account I cannot say. However, I believe Castaneda had extensively delved into altered states of consciousness and is telling us that the lucid dream state is of utmost importance in the spirtual practices he has followed. Carlos is recounting Don Juan's teaching methodology. The methodology is not a logical exposition of the entire subject matter. It is a series of "tricks," such as the riddles used by a Zen Master, which the teacher uses to prod the student toward spiritual realizations. The student is instructed on all the workings of a grave and serious system and given classifications, rules, laws of how the system operates, things to look out for, etc. The teacher knows the system he describes is only a description of reality and not the reality itself. He is describing a mythical world but insisting to the student it is all very real, because it is the only way he can push the student to awareness, enlightenment, eternal life. This spiritual quest is what this book is really about. During this quest the line between fantasy and reality becomes blurred as it must. The Art of Dreaming is NOT mere entertainment (although I personally found it very entertaining). It is not factual. It is a profound spiritual work. But, as one other reviewer pointed out, you need to live it (to some extent) in order to begin to understand it. My advice is this: Have two dozen 30 minute in duration lucid dreams (if you can, yes that is a challenge) and then re-read the book; until then, withhold your judgement.