Originally Posted by Dr Jabadski

Marginally related to the question. I always check in 8-24 hours ahead of time and (if possible*) always print a hard copy boarding pass before I get to the airport, even when checking skis and bags. IIRC, there was a situation years ago, before boarding passes on mobile phones were common, when all of one airline’s computers went down for a few hours or a day. Boarding passes could not be printed at the airport, only those who had printed boarding passes before getting to the airport were allowed to board.

Hard to imagine that happening today but I still like to have a paper boarding pass in case Murphy’s Law and MacGillicuddy's Corollary rear their ugly heads.

(* Occasionally check in while away from home without access to a printer.)