Anyhoo, about 15 years ago I had work-related stress and severe insomnia for several weeks, and eventually went to a social worker to talk the shit out. He recommended I get assessed for ADHD, and gave me a number. I called. The woman who answered asked how old I was. 40, says I. "Well..." she says sympathetically, "You're really too old for ADHD. We only test children for that." Wait, what were we talking about?
Me, thinks you are painting with a bit of a broad brush about dopamine. As it's a combination of factors and chemicals in the brain that create any one reaction. Furthermore, I would argue with your premise that we are sensory deprived or bored. In fact, I would argue that we are overly stimulated. But of course, that comes from my general perspective as a person who thinks the "here's a million things for you to look at, distract yourself with" is downright annoying. Again that might be because of the way my brain works.
There is some truth in that. I think it has to do in part with our education system which is set up to favor girls and their modality of learning, which of course is about the exact opposite of what boys need. Yea, she's and idiot. Adults normally get referred to a psychiatrist who specializes in adult ADHD.
This thread is worthwhile not only because it's an interesting topic/debate, but because it has introduced "Mr. Snitchers" into the Wordforge lexicon. Rapey McCreepypuff would be proud.
TV and most video games, surprisingly, just spur dopamine production; they're not actually stimulating. Commuting is boring as hell. Sleep isn't boring, but you're not terribly productive while sleeping either. Most people's work is minimally stimulating, and boring after a short duration. Once you've got the job figured out, your brain naturally wants to move on to something else. What's that leave?
^ That's certainly the way I see it. I get bored easily if there is nothing knew to focus my mind on.