The controversial psychoanalyst said that our brain protects us from disturbing thoughts and memories by repressing them.
Modern theories suggest it's not as complicated as that... Sigmund Freud (1856-1939), also known as the father of dream research, gave psychoanalysis as one explanation for why we dream.
But Freud had little understanding of the REM and NREM sleep cycles - and modern day dream research has pointed us to a number of other theories of dreaming.
- [Voiceover] Let's look at our gentleman in the middle. That raises the question, do our dreams have a meaning?
So if he's thinking about money, relationships, even weird and wonderful things like monsters chasing him down the road, what does that mean? Now, along came Sigmund Freud, a prominent neurologist and psychoanalyst, and what Freud said in his theory of dreams is that dreams really represent our unconscious wishes, urges and feelings.