Why are you almost always so much more vivid than dreams? It just seems so unfair. Sometimes, during a particularly realistic nightmare, someone in the dream will "drug" me, then laugh like Cruella DeVille and say something like, "this will make you think it was all a dream... but it wasn't." It's like my subconscious wants to taunt me. (Fortunately, my subconscious usually doesn't realize the importance of proper casting; I might be fooled by the in-dream drugging scenario if the person in the villain role were someone who hates me in real life. But the ghost of Richard Nixon isn't quite as believable, at least not once I have some caffeine in my system.)
Maybe people need to have a balance of good dreams and bad dreams for the universe to stay properly aligned. If so, maybe the vivid nightmares are just dreaming karma. Sometimes (rarely) I have dreams where I realize that I'm asleep, and all sorts of fun ensues. Actually, that's a lie. I suppose it's more fun than an I-have-no-control nightmare, but all that usually happens is that I think, "well, if I'm dreaming, I can fly," and then I decide it would be fun to fly around and have a bird's eye view of my house.
Come to think of it, I hope no one ever drugs me in real life. I could end up living out that one episode of Jem where the new Starlight Girl gets talked into doing some of drug (PCP? On a Saturday morning cartoon?) by the super-creepy drug dealer at school, and then thinks she can fly out the window.*
* That episode really freaked me the eff out; it was almost as disturbing as when I "borrowed" one of my sister's "Sweet Valley High" books in the 3rd grade and it turned out to be the one where the girl OD's on cocaine. Talk about nightmares. It's probably why this guy freaked me out so much.