that is really awesome, sometimes it does feel like the dreams one has are amazing adventures

That's a pretty elegant explanation. I'm usually more shameless and just kind of take things. I think I might use this as an adventure hook for my players. Kind of like the game psychonauts where a person's psyche is the game level and their inner demons manifest themselves as monsters.

I'm bumping this because I might make use of it in the game I'm currently running. I also took the liberty of making a few tweaks the writeup (I hope you don't mind, and I'll point people here, so they know where I got the idea from). Here's the "final" version I worked up.

Psionics: Dream Walking: This is actually the most common of powers. Some have it and never even realize it. Unfortunately, most that possess this ability lack the will to control it, and either go mad or wander the Dreamlands unable to differentiate the Material from the Immaterial. A Dream Walker, when asleep and in REM state, releases his Dreamself (Astral Form) which can then traverse the Multiverse through the Dreamworlds. A Dream Walker can explore vast unknown worlds while sleeping (Players and GMs should work together to figure out what worlds the PC explores). They can live hundreds of years in a single night. With practice and control, many a Dream Walker has become a successful writer. Dream Walkers include such celebrated writers as  H.G. Wells,  H.P. Lovecraft, Tolkein, Edgar Rice Burroughs, and even Kepler. However, recalling the experiences one had while dream walking is difficult. Even the most experienced dreamwalkers can distort their recollections of their dreams. Recalling a dream in its 100% perfect form is extremely difficult (I+C/10) = % chance of accurately recalling everything the PC experienced during their Dream Walking. On an unsuccessful roll, the PC will remember bits and pieces of those experiences (GM's discression).