only, not having a dream is impossible. Every mamal dreams every time they go through a Rem cycle, which is about 5 times a night on average i think. So u dream roughly 5 times a night, its just how well you develope your dream recall that counts. I was only able to remember all of my dreams in a night only once ever... oh yeah, and cows can only dream when they sleep lying down, heheh. I just thought i had to mention that!