As a tail-end Gen-Xer, I've had the remarkable experience of going from handwritten rolodex entries and curly-cord rotary phones through to today's cloudborne contact lists, which instantly let you contact people in any of a dozen ways within seconds, whatever sort of phone or device you're holding.

My generation's ability to remember phone numbers is a bit of a coccyx – the vestigial remainder of a structure no longer required. And there are plenty of those in the age of the smartphone.