Why do we only remember some dreams?

Why do we only remember some dreams?

Chris Idzikowski (Director of the Edinburgh Sleep Centre) gives expert video advice on: Why do we dream?; What is a dream?; Does everyone dream? and more...

I suspect the difference between nights is all probably almost one to do with body temperature more than anything else. Body temperatures partly correlated with alertness and awareness of what's going on and just slight variations in body state are enough to create a difference.