Write about your paracosms!!
I just read back some stuffs I wrote about a paracosm I created based on a dream like 5-7 years ago and I am sobbing. Yes, it's written badly. Yes, I'm judging myself a little but still-
Most of it is nonsense since I forgot some of the lore (like there are a lot of characters being mentioned with absolutely 0 clue of who they are & I can't remember shit about them so it's v frustrating) but I'm so happy I still thought about writing and keeping parts of this story because it's amazing and exciting and I'm so proud of myself, I can't believe my brain came up with all of that based on one fucked up dream!?
My point is : write it down. Doesn't need to be well written or make 50 pages but one day your future self might find it back and be amazed at how creative you are. One day, you might miss these worlds so keep a trace of it to help you remember how awesome they are.
These will make good memories to look back to, I promise.