Going from living in the UK where the only time the power went out was some numpty from cable and wireless drilling through the line, or the miner strikes, to living over here where we lose power at least 3 times a year and sometimes for a week. It really doesnt take long for the supermarkets to run out of everyday items and if the petrol stations can't pump their petrol or run out, it get crazy.
I learnt after the ice storm of 2009, i've now got LED lanterns, spare batteries, enough canned food, and water to last about 2 weeks.