"Thank God you woke me. I was having an eight hour dream about a ball of yarn. It was so boring, I tried to go to sleep, but I already was." -- Randy Hickey (My Name is Earl)
Dreams occur during active REM sleep and there are literally hundreds of interpretations of how and why we dream. Most disturbing dreams occur when there is anxiety present, just as being awake and having anxiety can create disturbing thoughts and visions.
The old neurophysiology saying about the nervous system is that it: Waxes Wanes and Mutates. There is some evidence that our brains contain more neural interconnections than all the atoms in the universe. We are complex beyond belief....
A raw nervous system expresses itself in diverse ways simple as that!! Today a bad dream yesterday pain tomorrow maybe heartburn.