Yes, our brains evolved to have short focused attention. This means long focused attention is difficult for humans because our instinct is to constantly be on the lookout for prey, food, shelter, or mate. Short spurts of attention helped our ancestors survive in the wild. Doing deep focused “work” would have resulted in failing to realize that you were being hunted. Boom! Next thing you know you’re inside the belly of a lion or jaguar. Unfortunately, for you, you ain’t Jonah so God isn’t going to command the animal to spit you back up. But if he did… you’d be in pieces. Good luck trying to find a mate.