This diagram shows the link between emotions and memory.
The notes that go with this diagram;

(1) choice to stay in negativity could have the following reasons:
Find an answer to the problem (one should choose the 1.5 route occasionally to not get stuck)
When the 1-route is chosen to circle between Memory- and Emotion-, then a choice to feel bad is made.
This could be to:
Process the emotion and then move onto other thoughts/work
Seeking attention and/or help from other individuals
(2) Most people subconciously do a healthy detour through (2.5).
Mania is to get stuck in the (2) loop.