A couple of nights ago, I was on telly riffing on Joe Biden's pledge to keep punching and punching and punching at domestic violence. I concluded by suggesting he promise to smash a grapefruit in the face of domestic violence - and I was immediately barraged by emails from viewers who had no idea what I was talking about, and thought I'd flown the coop of whatever sanity remained. Alas, my cultural references are increasingly incomprehensible to those under, say, 112 years of age, but this particular one was once universally known: Jimmy Cagney shoving half-a-grapefruit into the kisser of...