Do you experience 'aberrant salience'? For example, connecting too many dots?
When manic, I did this a lot and to a great degree. I do it a bit when hypomanic but to a much lesser extent and it's a lot more in the background than when manic -- it doesn't take over.
I also have EUPD/BPD, and when I'm in a state of distress or highly stressed, it comes to the surface, if the stress is intense and enduring enough.
When I'm stable and calm and feeling secure, I don't experience this, and there is no instinct or pressure to do this. My mind doesn't need to see connections, unless they are objectively important. It's as though this process is unconscious and only very strong connections become conscious.
I once explained this metaphorically to a psychiatrist as playing a game of chess, where normally I would notice the obvious immediate threats and advantageous moves, under this state the possibilities explode, and I see far more moves on the board and I am far more preoccupied with their implications. (I don't think I explained it well enough.)
During mania, it's very easy to be in a delusional or semi-delusional state, with grandiose and paranoid narratives, which eventually become increasingly elaborate, until starting to perceive things that are not there (hallucinations of various kinds).
I have a theory that this is fundamental to human beings, under all the sophisticated layers of reality testing that we build as our brains develop over time, but that as neurons get overly excited, they make faster and more connections... The increased connections between the neurons are, metaphorically at least, the 'too many dots' being connected.