Do you mean to creating a community? There's a button in the header navigation to do that. An entire instance would be overkill.
Although, you might consider checking out !dull_mens_club@lemmy.world and !dullsters@dullsters.net. Those seem like the sort of vibe you're going for.
Ah, I think I understand. Although, my take on those dullster communities is that they're less about being a boring human but more of a recognition that a lot of tasks are pretty mundane but deserve a place to be discussed/celebrated. There may be value to be found in posting your successes and discussing them.
I don't know of any communities that are specifically about what you're looking for, but I guess you could also check in !adhd@lemmy.world and ask.