Why do we dream more profusely when we nap than we do overnight?

According to the expert we consulted, we dream just as much at night as we do when we take a nap. However, we recall our afternoon-nap dreams much more easily than our dreams at night.

While we are dreaming, our long-term memory faculties are suppresses. During the night, our sleep is likely to go undisturbed. We tend to forget dreams we experience in the early stages of sleep. The sooner that we wake up after having our dreams, the more likely we are to remember them. Any situation that wakes up just after or during a dream will make the sleeper perceive that he or she has been dreaming profusely. Dr Robert McCarley, the Executive Secretary of the Sleep Research Society, told Imponderables that women in advanced stages of pregnancy often report that they are dreaming more frequently. Dr McCarley believes that the perceived increase in dreaming activity of pregnant women is prompted not by psyshological factors but because their sleep is constantly interrupted by physical discomforts.