Neph,
I really don't either.
I just recognized enough to say "aha, ok, and then like building blocks, go to the next question to confirm or deny. I was pretty good at staying in my lane when it came to things like that. You don't have to be smart to follow the medical work that someone else has already done.
Similar to what a Designated Examiner did, I would memorize their involuntary commitment list (among other things, like reading and referring to the DSM-5 regularly for answer to questions), and when I would be assisting a patrolman, or whomever, would just roll through the list.
It also made the later interaction with DEs very easy, as when they would ask me their questions, I had done 80% of their work for them. They actually really liked that,as it sped up the process for holds.
I had a rudimentary understanding of how the synapses were not firing right, and I would explain it when teaching in terms to first responders like electrical wiring (discussing meth), where the insulation had been stripped away, and now the wires were "crossed"touching each others sending electrical signals to parts of the brain that were never intended, causing all sorts of issues. It was also the reason that once you do drugs like meth, your brain never actually recovers. You may look fine of the outside, but your brain is permanently messed up.
That was my young Patrolman 101 version, and it seemed to be effective in conveying the concept.
Like I said, not the brightest bulb, but I can pick up a book.