Remembering multiple dreams at once

Hopefully I'm posting this in the right thread, sorry I'm a total newb. And sorry for my bad English :P.
I'm here because I have a question about remembering dreams. I have tried to google this multiple times, but I can't find any related topics.

Here's my question: every now and then (at least once a month) I will lie in bed, getting ready to sleep and I will remember a dream. I randomly remember one of my dreams I once had. After remembering one dream some kind of 'door' opens in my brain and I start remembering multiple dreams that I had months ago, a year ago or even 10 years ago. I don't have a dream diary and the dreams I remember aren't special dreams or nightmares. They are just dreams that I once had, and remembered when I woke up.

Here's an example: I was lying in bed and I remember dreaming about one of my old schools, but as soon as I remembered that dream, my brain started showing me other dreams I once had, and starts to "weave" them together. I will remember the dream about my old school and as I see the hallway of that school my brains shifts to another dream that has a hallway. I remember that new dream, with the hallway and in that hallway I see..a flower. And again my brain shifts to a different dream I once had that involved flowers. To me it feels like a special "door" in my brain opens and it's showing me the dream memories I once made. I had one of these moments yesterday and I remember dreams I had years ago (10 years ago maybe) and I had forgotten about, because they have no special meaning at all.

Every time this happens I will remember about 10 dreams in about 30 seconds. I only have these moments about once or twice a month. If I would go to sleep now and I would try to remember a dream, I would just remember that one dream and I would have to force myself to remember another dream I once had.

I have no idea if I'm making sense :) but I have been looking for a word..or an explanation for these moments. I was wondering if there is a certain part of your brain that is active when I'm having one of these moments. Hope I don't sound stupid now, but maybe someone knows what I'm talking about.

Nah dude I have those as well I think it is just simply your own thoughts triggering the memories, but depending on how vivid and detailed those memories are it could be something more. Now If the dreams come completely out of the blue(which is what i think you said above) then its something entirely different I suppose, but what that is i have no idea, maybe you just have a creative mind or something:D