Wake up to pee, can't remember any dreams

They say that your body will hold in urine until the end of REM so you can go to the bathroom before the next sleep cycle beings. Holding this theory true would mean that you should have excellent recall when you wake up, since you just got out of REM sleep.

However, last night I drank so much water in hopes of waking up continuously. It worked. I woke up 3 times last night to urinate, all of which were over an hour apart from each other. The problem was that every time I woke up I couldn't remember anything about my dreams. Nothing. I even sat there for a few minutes and tried to remember what I had just been dreaming about but absolutely nothing.

It was only when I finally woke up 7 hours after initially going to bed that I remember my last two dreams. So what happened to the other 3-4?

Sometimes it is merely weak recall, as I've been having in the past little while. For the past little while I've only been able to recall small fragments when I wake up during the night, if anything at all. Do you keep a DJ that you use every night? You have to increase your overall recall to get the small bits too.

This may not answer your question, but you can improve your dream recall and dream quality.

Dream Bible - Dream Enhancers

Sometimes if you have other things going on in your life then recall can be very difficult. Also if you have an inconsistant sleeping pattern. When you wake up try not to move from the position you were sleeping in, that also helps with recall.