Weed gives all of your thoughts and ideas the same amount of reward via dopamine. People who trip out on weed are afraid of what they will do without complete control--they fear the wrong thoughts will manifest in the wrong behavior.
But in people who can adjust to weed, there is subconscious trust in the ability of the personality to make the right choice. Those who trip out are conflicted between self-loathing and fulfilling the wishes of others.
I have such good ideas when I'm high because I ignore a lot of quality ideas when I'm sober in favor of what will fulfill my wishes with the least amount of irrelevant effort.
When I'm high I can also rake through thoughts I avoid when sober. Before my sober mind can realize the thoughts are not that scary, my brain opts out of thinking about it, resulting in generalized triggers that inspire these repressed thoughts.
Repression is the process of rating how useful a memory is, using dopamine. A score of zero means there is no reward, meaning the information gets forgotten. A score of 10 means the memory is highly stimulating and the individual is preoccupied with the thought.
-5 means the memory threatens nervous system reaction, so the mind avoids the thought.
-10 means the memory triggers nervous system reaction (panic attacks, acute psychosis, etc).
A score of 5 means the thought is stimulating, but it is not an obsession. The thought inspires curiosity.
If a -5 cannot be avoided, it will probably become a -10
Repression is the process of taking a memory from around -5 to 0 or 01 without the passage of time or the resolution of conflict.
Dissociation is the process of taking a memory from at least -5 to 00.
00 is to denote memories that cannot be accessed, the patient cannot remember or be reminded.
01 is to denote memories that seem retrievable but that are denied.
-0 is to denote memories that are only retrievable in the presentation of alternate identities.
+0 is to denote memories only retrievable through hypnosis or drug use.