Why do I sometimes remember my dreams, and other times I don't?

Why do I sometimes remember my dreams, and other times I don't?

Professor Gizmo (Amazing Science Presentations) gives expert video advice on: What is my body made of?; Why do we get "goose bumps"?; How do I catch colds? and more...

Sometimes you remember your dreams and sometimes you don't. A lot of people that are really into dreams, what they will do is they will immediately upon waking up they'll write down their dreams because it really is hard to remember your dreams. The dreams that we are going to remember are usually the last ones that we have and sometimes the ones from some of the deepest sleep which is called REM (rapid eye movement). You can see when somebody is in that state because their eyes are closed but you will see the eyes moving around underneath their eyelids. And this is the type of sleep that will produce the dreams, and the only way to really remember them is immediately upon waking up that you write the dreams down and then you can remember them. Otherwise, they will pass through your memory very quickly.