If you're sensible enough to live 'WELL" within your means (which many can't), then it's reasonable to assume that you will be immune from the unforseen.
TBH, petrol price increases, which started this sub-debate, are piffling on the scale of things. Lots of families are going to dump private medical insurance this month because of recent increases. When commodities or essential services escalate beyond inflation rates and outstrip wage increases, hard decisions are necessary and something has to go.
Did you have a mortgage in the late 1980's? I did, and I guess I must have been like you, because when interest rates blew out to 17.5%, defaults on mortgages blew out unbelievably across the nation. The magnitude of the increase was beyond anybody's anticipation (it was the time of Keating's infamous statement that "this was the recession we had to have"). I was fortunate (or clever) enough to have kept the size of my mortgage well within my capacity to repay and the fortnightly instalments were pretty awful, but when the rates fell, I was able to maintain the repayments at the higher rate and the mortgage really started to decrease. If I'd listened to friends, or taken my wife's income into account when we took out our mortgage, we would have been in real strife. (Young people arranging mortgages these days can't even imagine interest rates of 17.5%, but during the early 80's, the average rate was around 11 to 13 percent and they hurt back then, too.)
More recently, the increases in electricity prices over a number of consecutive years has meant drastic cut-backs for many households and those on limited or fixed budgets like pensioners probably suffered the worst. Do you think they failed to prepare themselves? Hardly.
It's pretty easy to be dismissive of somebody complaining about the increases in fuel or food or whatever, but some things are not so cut and dried.