Why is it impossible for some people to simply shut up?

Yeah ,I get your drift. The ones who talk sport get me ,so I tell them I have no interest in sport at all and they spend an hour telling me what i`m missing and all the highlights of last nights game.Break into their flow by telling them you collect novelty can openers or you work part time at the mortuary -or the clic conversation stopper -you`re a railway enthusiast and you won`t see them for dust .Did I ever tell you about the time I saw a cl 47 with 14 on thrashing up Crewe bank .....