Does anyone know possible causes for rarely-dreaming-at-all?

I very rarely remember my dreams.

In order for me to remember a dream I have to be unexpectedly woken up (at the right point in my sleep, obviously) and then I have to fix that dream -- by writing or talking or just repeating the key points in my conscious mind -- or it will fade away in a matter of seconds.

For all practical purposes I don't dream.

On the other hand I can do lucid dreaming, but the conditions have to be there: a morning when I can doze and no one will interrupt me. Happens rarely :-(