Apparantely The Black Eyed Peas' tune I Gotta Feeling was written by will.i.am in his sleep. He admitted recently that he often feels inspired by his dreams, and jots down his ideas for tunes as soon as he wakes up. Sir Paul McCartney is another one, he famously came up with the melody for classic Beatles track Yesterday while sleeping. Do you do anything out of the ordinary in your sleep?
Dreams are funny things. Sometimes they're so vivid, you can virtually recall every detail but mostly, I find as I'm getting older, the memory of it fades away as the brainwaves in your head begin to adjust to the waking state.