The joke to me seemed to be poking fun at correlation and causation. In a literal sense, people get pets for different reasons. A lot of people get cats becaus

The joke to me seemed to be poking fun at correlation and causation. In a literal sense, people get pets for different reasons. A lot of people get cats because they're more independent where dog owners cite "having a companion" because dogs have a closer relationship to humans through domestication. Animals are still animals, domesticated or not. They'll get fearful or angry based on correlation of past experience just like you and I will. The only difference is that they can't explain themselves like you and I can. Anecdotally, I know my dog is terrified of fireworks, but I also know she's not gun-shy. I also know she doesn't like full face masks (like motorcycle helmets), and that she's ready to defend the house if there's a knock at the door. All of which sound relatively terrifying to the average person when she reacts to them, however, when she is actually confronted with the person on the other side of the door, the person behind the mask, or seeing the fireworks that go "bang" she'll flop on her back and ask for belly rubs.