One such hypothesis for sleep-related rhythms is that they are the brain's way of disconnecting the cortex from sensory input. When we are asleep, thalamic neurons prevent penetration of sensory information upward to the cortex. This gives the cortex a bit of a rest and explains why people who suffer sleep deprivation suffer a loss of critical thinking abilities and are prone to poor judgment. Another hypothesis is that dreaming plays a role in memory processing, especially with emotional memories. During REM-sleep, the amygdalas, which play a role in the formation and consolidation of memories of emotional experiences, are quite active .
Dreams are mechanisms that inform and guide our feelings and emotions.
In short, this theory maintains that dreams are a way for us to express our desires and fears that, for whatever reason, need to be expressed but are not expressed when awake. If this is true, it would seem to follow that only one very intimate with the dreamer should attempt to interpret a particular dream. Dreams are very personal and speak to the specific emotional life of the dreamer. This theory seems to be based upon the fact that most dreams are about things that have occurred within the past day or two and reflect the dreamer's present life and concerns, including unresolved feelings. We may have anxieties or desires that only our dreams can reveal.