Because, honestly—you're not that different.
If you were completely real with yourself you'd admit that when you watch tennis, you want to jump and down like an asshole watching the Australian Open, too. It's goddamn FUN! Why do you think they made those video games so you could "play" tennis like a real tennis player but without having to leave your home in weird tennis attire that your friends would just make fun of? This Golden Retriever gets it. Just stop judging and be the dog, OK?