2Dreams are conventionally defined as mental experiences during REM sleep that are often based in vivid imagery, have a storylike quality, are often bizarre, and seem real to the dreamer. Many recent theorists have, however, questioned almost every aspect of this definition. We know now that people dream in non-REM too, although the dreams are less story-like and vivid in imagery. Also, recent research shows that content is usually not bizarre, and that dreamers are often aware that they are dreaming. Thus, the scientific conceptualization of dreaming is changing.Research shows that the content of dreams is usually familiar. Common themes in dreams include things like falling, being pursued, trying repeatedly to do something, school, sex, being late, eating, being frightened, etc. Children’s dreams appear to differ from those of adults, with preschool children reporting bland images with no story lines when awoken from REM sleep (if they recall dreaming at all –children under the age of 9-11 report dreaming only 20-30% of the time when awoken from REM sleep, as opposed to an adult’s 80% of the time). Between 5 and 8, children begin to report dream narratives, but these are not well developed. Adultlike dreams develop at around 11-13, suggesting that dreaming is a cognitive ability that develops gradually.Freud said that the contents of waking life tend to spill into dreams; he called this day residue.People in Western cultures pay little attention to dreams as meaningful messages in their lives, while people from many non-Western cultures are likely to view dreams as important information about themselves, the future, or the spiritual world.