Did you know that we dream both in REM and non-REM sleep cycles? Non-REM dreams are typically of positive nature and they tend to carry a lot of the stuff from our daily staff. Dreams in REM cycle typically involves the future and future challenges but they are quite melodramatic in their presentation. They say that the cause or the function of the REM sleep is unknown but if you lack it, then you will not be able to learn tasks of complex nature or even understand it. REM sleep happens every 90 minutes in an adult. So if you don't get enough sleep or any sleep at all, then it's likely you are acting out on impulses on a daily basis and perhaps you lack complex reasoning and intellect. You might want to see a doctor in that case. There's a very specific reason why we sleep and why we sleep especially at night.