The central conflict of dissociation is the need to know and not know at the same time.
When something happens that overwhelms us and is too much for our brains and bodies to process, then we are faced with the desire to not know what we do in fact know.
Dissociation is the mental gymnastics that helps us to both know and not know something.
In its most extreme form, dissociation allows the conscious, waking mind to not know the thing that has happened.
In more subtle forms it may be knowing the facts of what happened without really being in touch with, feeling and understanding the ramifications of what happened.
Dissociation is not inherently bad or wrong, but when it is needed too often and utilized too much, it can become automatic.
This causes problems because although we may not want to know that it has happened the knowing lives on in the unconscious and in the body, both of which will send hints about what they still carry, often in the form of symptoms.