where spare time goes to die

Our dreams are frequently full of strangers who play out certain parts – did you know that your mind is not inventing those faces – they are real faces of real people that you have seen during your life but may not know or remember. The evil killer in your latest dream may be the guy who pumped petrol in to your Dad’s car when you were just a little kid. We have all seen hundreds of thousands of faces through our lives, so we have an endless supply of characters for our brain to utilize during our dreams.

From The Top Ten Amazing Facts About Dreams