American rocker Sheryl Crow had such a realistic dream about writing songs with Sir Paul McCartney, she is amazed he can't remember it too.

The All I Wanna Do hitmaker, 43, is always disappointed when the ex-beatle insists he has no recollection of the surreal situation, even though it was conjured in her own vivid imagination.

She says, "I used to have a dream that I was sitting in a tree with Paul McCartney, and that he and I wrote a song together.

"Whenever I see him, I always say, 'Do you remember the time we wrote that song on top of a tree?'"