Why do some people book and pay for flights, come to an airport, check in and then don't board their plane? It happened the last time I flew, when my plane was delayed while airline staff removed the bags of a no-show passenger from the plane. Today I watched as an airline employee at the neighbouring gate paged a passenger in vain, and presumed the same thing had happened. Do some people suddenly get a fear-of-flying attack, change their plans at the last minute or get stuck in the toilet (or the bar)? Maybe there are incredibly rich people out there who have no intention of flying but just do it to mess with the rest of us.