Sometimes I wonder where my dreams come from...

This one came when I was taking a short (about 2 hour) nap in the evening because it'd rained earlier and I felt sleepy.

( A long, and very disturbing, dream )

I woke up at this point, and I was so scared of what was happening, even though it was only a dream, that my heart was literally beating like crazy and I was seriously worried. I definitely haven't read (or seen, and so on) anything that even talks about this kind of thing, and so what I can think of to try and rationalize why I might have had this dream is that either my mind stitched together pieces of other things I'd seen or read (such as Silent Hill or Dean Koontz's "The Vision") to form a rich tapestry, or else... I might have seen something that really did happen in real life in the past (and in which I might even have been present?).

*tries to find things to do to erase the memory from his mind*