Habitual behavior or the ‘trained’ mental and emotional responses that protect the psyche are called defense mechanisms. In your early years, you are like a sponge, absorbing incoming information to understand the person that you are becoming. Sometimes the feedback you received was positive and at other times, it may have been negative. Just like the other mechanisms in your body, the psyche has a way of protecting itself from pain by employing defensive measures. It can block any incoming information that causes you to feel ‘uneasy.’
At some point in your life, a type of subconscious net began to both trap beliefs within the unconscious, while rejecting anything that goes against what you were trained to believe about yourself. A defense mechanism can be as simple as the psyche’s ability to block emerging or transformative ideas. It can be as complex as how it attempts to work through difficult or repressed emotions by leading you to confront them through difficult experiences or through dreaming. These are situations that hold a 'certain fascination for you,' because they embody an opportunity to overcome what you are repressing. In this case, you tend to attract the situations that you need, while these are the very situations that you would also, rather avoid. The more you ward off this transformative aspect of the psyche, the more these issues will become the symbolism of your dreams and daily experience. Abreactions, like the Freudian slip, show the power of the psyche in its desire to break free of repression.
You spend two-thirds of your life building belief structures that are disassembled during the one-third of your life that you spend dreaming. The human body was designed to take in, process and release energy. While it also has the ability to store energy, this energy will still find ways of dissipating. See Dream Basics and Dream Processing.