Hello everybody
First, sorry if i don’t speak english very well, i’m french 
I want to remember my dreams so i have begin to write them, but it is always hard to write one page of my dream when i just woke up, and i feel very tired when i do that.
So is it really a must to write my dream after i woke up, or can i just try to remember the story of the dream in my mind and it will still work ?
Of course you can try to keep the dream you just had in your memory and write it down in the morning…It may work, but you’ll forget many many details if not the whole dream. So it’s really better to write your dreams down the moment you remember them.
If you don’t want to write your whole dream down, write short keywords instead. You might forget the details too, but it will work better than remembering the dream only by memory. Do you write your dreams down on paper? If you do, try some different media, like your cell phone, your iPod or a voice recorder. Maybe it’s only the handwriting which makes it hard for you to write your dreams down.
This is also a very nice guide about keeping a DJ.
Personally I always go through the dream in my head until I can’t remember anything more (I always keep my eyes shut and lie still while doing this), then I voice record everything and transcribe it when I wake up.
I will try a voice recorder, you’re right it’s the handwriting which makes it hard and boring, and thanks for the guide, very nice post 
@Laurelindo I do this too, and it’s a very good way to remember more details about the dream