Go back to the video and read the Comments section. The readers add their own favorite jokes. I read it for over an hour and just touched on the treasore trove of good and great ones. Here is one of them: A linguistics professor was lecturing to his class one day. "In English," he said, "a double negative forms a positive. In some languages though, such as Russian, a double negative is still a negative. However," he pointed out, "there is no language wherein a double positive can form a negative." A voice from the back of the room piped up, "Yeah, right."