When I was a kid, my dad took the family to Yellowstone. I clearly remember a guy leaning over a guard rail trying to get a close-up photo of a bear. Then the bear swiped his face with its claws. It was a big deal, with an ambulance and ranger vehicles and whatnot. I felt sorry for the bear.
On a motorcycle trip, I stopped in Custer Park in SD. I was stopped, and a bison came right up and was rubbing against me. Aside from not wanting to become his boy toy, I was concerned about what to do. I thought trying to start the bike and take off might spook him. So, I just didn't move. Apparently I wasn't exciting enough for him and he left.