Why can't I have normal nightmares?

When I have dreams that are trying to tell me something, they are hyper-real. Every color is rich, every edge is sharp, every person has depth and autonomy. It's quite nice that I dream mostly in fantasy/sci-fi. What's not nice? Is that I have hyper-real dreams that are calculated to upset me using a wide variety of weaknesses, of which fear is the least part. If the dream bothers me, I'll be more likely to remember it. Yay for the ruthless logic of the unconscious mind.

Last night's dream featured me sneaking into the underground base of a lunatic who's breeding giant snakes that he can train to destroy cities, myself intent on stealing the regulator box of the catalyst/device that makes the scent hormones he uses to control the snakes. Without control of the animals, all I have to do is collapse the entrance, and the rest of the problems will take care of themselves. :j

The interesting twist this time is that I'm stuck in an ouroboros loop, because even in my dreams the plans never go smooth. I'm tense and sneaking around in the pre-dawn quiet, and it takes about five minutes to get from the compound wall to the tiny entrance. When your senses are that stretched out, five minutes is a long time to be sneaking around patrols and ducking behind things based on the sound of quiet footsteps. When I get into the entrance to the tunnels, time loops back to the beginning. And every time it loops, things are a little different. Patrols are in different places, or going different directions, or I have a cut that's leaking blood, and the patrols dogs can smell me, and they sound restless. Every time I get to the carved stone entrance and slip inside the tiny 4' by 4' aperture, stone slick and cool beneath my palms, it all restarts. Eventually I woke up, but my shoulders were so tense that they still ache, because of something I thought I was doing in my sleep.

Now I just get to figure out what it means.