There is, of course, the issue of major catastrophe. For myself, I am more concerned with the daily potentials. I hike in the White mountains, commute over an hour each way each day through rural andurban areas, I do home repairs and auto repairs, live through snow storms that put out the power for weeks at a time with an electric well, Being prepared to deal with these things is a very similar thing to dealing with any survival situation of any scope. Most of these situations resolve themselves within a month or so. I learn to melt snow, make fire and water, grow, hunt and harvest food, mend and manufacture clothing and shelter not because I expect to be living beyond thunderdome but because I want to be a little better prepared to deal with life. If I happen to be one of the few who survive to live beyond thunderdome then I will be better prepared for that too. That is not a goal just a positive happenstance.