ADHD hyperfocus: characterized by intense, often unwarranted focus on one task, area, project or undertaking. This focus can be a brand new endeavor or a favorite project-type such as the habitual plaintiff who can't seem to cease taking people to court.
We'll call the former (the new endeavor type) a dillettante, and the latter the plaintiff.

Both types of ADHD hyperfocus share certain qualities. Neither are particularly good at focusing on the uninteresting for very long. Their ability to focus on the uninteresting is shorter than the average person. For this reason they can appear aloof, spacey, or even to take nothing seriously. Neurotic and hypertalkative is also common, especially if they have a hair-trigger hyperfocus.

The dillettante switches from hyperfocused endeavor to hyperfocused endeavor throughout their life. For example, the contractor who takes on jobs, tries to do too much, which turns them into two-month undertakings and ends up losing money. Each hyperfocused endeavor is a crisis and a reason-to-live wrapped in one.

The plaintiff is best characterized by their hair-trigger hyperfocus. They can be set off by certain hot topics. Everything else that isn't a hot topic is either analyzed in relation to a hot topic or breezed through with little focus exerted. For this reason they can appear neurotic and obsessive. Everything from street signs, other people's mannerisms or their own mental fidgeting can trigger outpourings of hyper focused thought.