Sometimes the upside is just being different. I heard about a group of cattle, and one of them was ill, while the others feasted. The feed was tainted, and so only the sick one survived.

Though, with ADHD, I think it's definitely more than that. It doesn't just make it hard to focus, it makes it hard to focus on what you need to, until the moment that it is obviously now or never. Focus, though - there's tons of that, flitting about, and sometimes grabbing you up and running away with you - sometimes for months. I would imagine that there are a lot of novel discoveries attributable to it.