It’s rare in life that fantasies come true, so we are giving thanks and, frankly, just trying to process the news just out from Buckingham Palace that Kate Middleton and Lady Mary Crawley are about to become inseparable best friends — gabbing over tea, trying on fancy gloves for impromptu photo shoots, laughing hysterically over “Who’s on First?”-style jokes related to whether they’re talking about Mary’s baby George or Kate’s baby George. O.K., O.K., we are getting wildly ahead of ourselves.