A robot walks into a bar and asks for a beer. The bartender says, "Sorry, we don't serve robots here."
"Oh, that's okay," says the robot, "I'll just stay here until my battery dies."
And it does.
A spider walks into the bar and sees the dead robot. "Wow, this is funny for a lot of reasons," he says. "First, it's funny because the robot doesn't care about where it takes its final journey. So even though the bar is not an appropriate place for a robot to die, that doesn't matter to the robot. It's also funny because the robot is more aware of its own mortality than the bartender is. And finally, it's funny because it's ironic that a robot would die in a bar, since robots don't drink alcohol."