Well, you have a choice.

Do you wanna have a nice, detailed record of one cool lucid dream, or do you try having another one and taking a chance of not remembering them too well.

Some people prefer to write it down, because it can happen, that you just fall asleep and don't have another lucid and you won't remember it in the morning. Why risk it, if you already had a nice LD? If you don't remember having it, than it's like it never even happened.

So try to have a DEILD, but if it's not happening, get up and write you LD.