Those people who have CASH and are close enough to a store to buy food, meds, etc., will be very few and far between.
Credit and debit cards will be useless.
And even if I own a vintage car, how can I pump gas to fill the tank?
And on and on. Pray that (God Forbid) if this event happens, you and your family are within walking distance of each other or else there will be no way of getting home again or even communicate "location".
A bicycle is fine, till someone shoots you to get it.
Can you say "anarchy"?
I've thought about this one in particular.