from what i've read about it (again mostly from this dude Carl Jung who i spoke about in the "lost thread" thread), that phenomena is a result of the fact that the psyche basically isn't "bound" so to speak, or chained by space and time which are relative.....(dono if i'm explaining that clearly)
that's actually one of the basic premises of Dali's most famous painting, The Persistence of Memory:
Style as i'm sure u know cuz i remember u buildin on Dali in a thread i made a while ago, he was all about expressing his psyche--the deep "unconscious" psyche, the realm of dreams..
i've definitely had both of these happen many times:
-your dream feels like it's been going on forever and then u wake up in the morning amazed that it's over and wasn't real (since it seemed to go on for so long)
-you sleep hours and hours (this happens to me sometimes if i'm trashed) and it feels like u were only out for like 15 mins..