Everyone has had an elderly relative incapable of handling some kind of electronic device. The now outdated talk of how only kids know how to program video recorders is legend. One story I heard is how it is because of the way older generations' mental models of technology have developed and then crystallized. They grew up in age of mechanical dials.
By and large, outside of high tech labs, each control, button or lever, had only one function - you press something and it affects some real life mechanical or hydraulic system. As a consequence they just couldn't get their heads around how one control can have multiple modes of input, which is standard fare in the modern electronic age. By this I mean, press the button and one thing happens, alter the state (say by cycling through a menu using another button) press it again and something else happens.
It seems simple to us children of the seventies and eighties, but to your average 50 year old, this is mind-bogglingly complex and unknowable like trying to imagine the fifth dimension.
It seems interesting to think about how technology will develop over the coming 50 years and how we might just not get it. Perhaps it will seem incredibly alien to people that you won't always be contactable, or that people don't know where you are, or to have an instantly accessible library of information about everything you see and do.
Our quaint little button pressing ways will one day seem hilariously outmoded I am sure.