Why is it that some nights i have lighter sleeps compared to other days? by the way, when my sleeps are lighter, i have more dreams.

Various reasons: Most people experience nights when their sleep pattern is lighter than other nights. Incomplete relaxation, stress,anxiety,depression,late night eating,caffeine products,naps during the afternoon,physical discomforts are some reasons. Usually dreams are more prevalent during periods of sounder sleep although they can occur when half awake and half asleep.