I think dreams are like echo's of what happens in your day, and your brains way of coping with that information collected. It's like computers (matrix check..lol.) where all your memory is stored collectively, everthing you have done is on file, your brains way of deciphering anything that is usefull is like flushing a toilet; you always have the water, but the crap you learn gets flushed. Sometimes the info is too large for a normal flush and requires extra resources to accomplish it, thus, taking away your normal echo and intensifying it to a point of semi-consiousness and making your dreams seem more real than they are. Cos, your brain is more actively aware of the situation. Saying that, I'm no psychologist, so that is just my opinion.
Some dreams are mad tho. and it bears thought to how they are pieced together, whether it's a mindscape, or a congestion of knowledge.
I used to have the dream where I was flying all the time, but I just couldn't get as high as I wanted, you know the one.. Your flying over the hoods of cars and your within grabbing level of the people on the street.. and you can psychially feel yourself trying to climb higher but can't. Tis wierd.
But yeah, Lucid dreams are very real and bare thought to what they mean.