Your mind is a home, with an upstairs and a downstairs.
Upstairs, in your consciousness, things are well-lit and regularly swept. Friends visit. Scrabble is played, hot cocoa is brewing. It is a pleasant, familiar place.
Downstairs, it is older, darker and much, much freakier. We call this basement the unconscious mind.
The unconscious is exactly what it sounds like: It’s the stuff you don’t, won’t and/or can’t think about. According to Freud, there are dirty pictures of your mother down there. According to Jung, there are pipes, wires, even tunnels down there that connect your home to others. And even though it contains life-sustaining energies (like the fuse box and water heater), it’s a primitive, stinky, scary place and it’s no wonder that, given the choice, we don’t hang out down there.
However, your pleasure, your sanity and even your life depend on occasional round trips. You’ve got to change the fuses, grab the Christmas ornaments, clean the litter box. To the extent that we keep the basement door sealed, the entire home becomes unstable. The creatures downstairs get louder and the guy upstairs (your ego) tries to cover the noise with neurotic behavior. For some, eventually, the basement door can come right off its hinges and the slimy, primal denizens of the deep can become Scrabble partners. You might call this a nervous breakdown or psychotic break, it doesn’t matter. The point is: Occasional ventures by the ego into the unconscious, through therapy, meditation, confession, sex, violence, or a good story, keep the consciousness in working order.
From Dan Harmon’s Chanel 101 post on story structure. A great read.