CNN  —  When frazzled twentysomething traveler Jennea arrived at London’s King’s Cross railway station on December 15, 2013, the station was absolutely packed. Carol singers in one corner were singing with gusto, collecting money for charity in brightly colored buckets. Gathered in the middle of the Victorian concourse, crowds of travelers stood, wrapped in coats and scarfs, looking up at the departure boards, waiting for their platform to be announced. Passengers jostled past each other, armed