I'm going for a swim

I liked this series. I thought it was well cast and the story kept me interested. But on a completely separate note I want to draw peoples attention to the funniest thing ever to be filmed in history. "Im going for a swim". I cant stop laughing at that scene. He is in the middle of a conversation in his own backyard and then says "Im going for a swim" and jumps into the pool fully clothed! Its so funny I cant stop thinking about it. Why would he do that? What was the discussion amongst the writers and/or the cast when this scene came up? I need to know. Its just so odd. So very odd. hahahahaha