I've been writing down my dreams since I was in my late teens, so for over 40 years now. It takes a certain self-discipline to just get up and write them. I don't always have it - just wake up and think the dream was SO FUCKING AMAZING that I won't forget it. Then I forget it when I wake up later.
I recommend writing them down. One brilliant thing is that you read them back even after a day or so, and you've forgotten them so thoroughly that it's like reading something new. One not so brilliant thing is that you can never really capture your dreamscape, only a pale version of it, and some of them read back a bit boring, and you wonder why you bothered.
My story Monstrous Men was sparked by a dream. It's one of my favourites of my own stories. It's now been published twice. Focusing on a dictator and the people in his sway, it was prompted by an image of myself shaking a head of state's hand, and him putting some kind of food into mine. That doesn't feature in the story, but I think it's safe to say that such an image wouldn't have occurred to me. Here's the longer version of the story, in the splendid #EunoiaReview
My latest story out, The Solution to the Rooks' Rider, also has a short sequence culled from a dream in it, in which I saw somebody in a crowd who looked like me. It's here, in #platform4prose