Why live your life like you will be under siege any moment? The fact of the matter is that many people have responsibilities that make it important to be reachable. These moments may not occur very often, but when they do, a 3 hour delay can be end of a career.
For people that are retired, not much of a social life, or a job where responsibilities end at the sound of whistle, this type of life may seem totally alien.
Here's an example: when I was young, if my mother was expecting a call from a doctor about the results of a test, she would have to stay home for days at a time and stay off of the phone since these were the days before call waiting. Now in a similar situation, my parents can go about their normal lives and be notified by cell phone.
Technology is not your enemy - it is your friend.
I live in earthquake country. All prudent people are prepared to be self-sufficient for up to a week.
Surprisingly the world would survive without any of us for a week - even you!