I have ADHD and hunting and fishing are some of the most engaging things I can think of. Spearfishing can keep me focused for an entire day. I also love working on my equipment and researching hunts. This is all boring to everyone I know. I guess the key thing is that ADHD isn't an inability to engage or focus at all - there's a degree of selection involved.

For what it's worth, I never hop out to examine rocks. Some people with ADHD might suffer from impulsive distracted behavior like that, but certainly not all.