Dude: "I know two things about sloths. And one of them is a lie. Either, their metabolism is so slow that they only poop between once a week and once a month, and when they do, its the time they are most vulnerable to predators. Or, their brains move so slowly that they sometimes mistake their arms for a tree branch."
Me: "So the fastest a sloth ever moves is when it's plunging to its death?"
Dude: "I'm pretty sure the metabolism thing is the truth."
Me: "Yea. The tree branch one is a Douglas Adams joke."
Dude: "Why do you know that?"
Me: "I know one thing about sloths, and it's that Douglas Adams is a jerk."