Looking at the dates when most people on this site signed up, obviously it was mostly during the Bush years. 9/11 emphasized our global vulnerability, Katrina demonstrated the federal governments almost complete indifference, the 2008 financial crisis showed how volatile oil prices are.
Much of the public showed an almost complete lack of awareness going into the 2008 financial crisis. I put my money in Europe then into cash and only lost 1%. I recall one day at work where I remarked that oil had gone up $10 in one day, and all I got was strange looks.
It was about in 2005 that i got The Fear about our long term economic prospects because projections showed the deficit exploding over the next decade, even though the White House declared almost daily that the deficit was "going down" in some relative sense. I put in 500 gallons of rainwater collection and gradually accumulated about 16 fruit trees that I water with the rainwater. I also bought good quality oil lamps, and I have several gallons of fuel. I have a kerosene heater for emergencies, and gas logs. This is not frivolous because this area has gone weeks without power from hurricanes, and it has gone weeks without power from an ice storm. I also decided to really tighten our belts, at that point when everyone else was partying with their savings.
We up-armored in weaponry in 2008, at least in part because of the ever increasing levels of overtly (if not actually cliched) Fascist rhetoric in the US (you know who are you are

), and we adopted a little guard dog. We have a few months of food staples on hand, and we picked a couple hundred pieces of fruit this year. Next year we'll experiment with canning and preserving.
Since 2008, things have calmed down quite a bit. But being "prepared" is just good sense considering how much havoc corporations and employers can rain down on anyone's personal life these days. I took business classes and I am starting my own business because most companies are mismanaged nightmares, and the GOP is pursuing a strategy of economic sabotage.