If I had a dime for everytime the Australian president shat himself in a McDonald's, I would have one dime, which is not a lot, but it's weird that it happened.
Australian President at McDonald's
Explanation
Explain Bear
Okay, so basically, the joke is that it's super weird and unexpected for the Australian president to poop his pants in a McDonald's. It's not a lot of money, but the situation itself is so bizarre that it makes the joke funny. You probably think McDonald's is healthy.