I'm one of those people who have vivid dreams and remember them after waking up. My dreams have often been creative fuel for the stories I write. Back before I published my first novel, I wrote a lot of short stories, and I estimate that more than a third of those story ideas originated from dreams. (For me, dreams work better for short stories than for novels because the events in my dreams aren't expansive enough to fill a novel.)
Unfortunately, I also suffer from insomnia in that I wake up several times in the middle of the night. In a perverse way, my insomnia helps my creativity because, while I'm lying awake in bed, I'll hash out a dream I just had. However, the downside of doing so in the middle of the night is that my brain isn't awake enough to filter content correctly. I can't count the number of times I've woken up at 2:00 am thinking that a dream was the greatest thing since the story-telling equivalent of sliced bread. But frankly, those dreams often weren't as good as I thought they were. There's something about the half-conscious state I'm in that makes me think that bad ideas are good.
If an idea passes my 2:00-am-half-brain-dead test, I'll log it in my journal for further consideration. I'll then read through my journal in the future, when I'm fully awake. I don't know how many times I've asked myself why I thought some of my dream-inspired ideas were any good to begin with. Thankfully, I'll catch those not-so-good ideas before they turn into stories that I subject my readers to.
Except for this blog post, which came to me at 2:00 am one night.