Well, dreams can be caused by three main things: the
representation of our unconscious wishes and desires, the
interpretation of the signals sent by our brain and our body
during sleep and the processing of information gathered during our
waking lives. In our dreams, elements and images that we see
during the day or during the week re-emerge creating a transition
between our waking lives and our sleeping state. Here are the two
main theories:
Memory Consolidation
The first theory behind dreams is the memory consolidation theory.
Dreams are constructed entirely from our memories and they act as
a way for the brain to perform offline memory processing. This
contributes to the retention of new information and turning short
term or fragile memories into long-term memories. It also helps
grow our cognitive capabilities… basically the mental action of
understanding and acquiring knowledge through different senses and
experiences.
Freud's Psychoanalysis
The second theory behind dreams is Freud's psychoanalysis theory.
His theory explains that our thoughts, feelings and actions all
come from somewhere. Unconsciously, we think about our desires and
our fears and how they make us feel. However, we repress them.
This meaning that we don't keep them in our conscious mind or make
anyone else aware of them. Freud believed that our dreams were
just a way for our unconcious mind to bring these repressed ideas,
desires and fears to life in order to make ourselves aware of what
we feel.