"Annual income twenty pounds, annual expenditure nineteen nineteen six, result happiness. Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery." -- Charles Dickens, 'David Copperfield'
But also: we've seen swings of +95% within the past 3 years -- so at the peak, people were complaining about an effective 5% pay cut.
And not everyone complains. I have a tiny commute, a professional job, and live in an expensive city where housing costs dominate -- so even double the gas price is a curiosity ("OMG I've never seen a tank cost that must") rather than a serious pain-point.
On the other hand, many people are far above that 4.8% average spend. They have long commutes and fuel-inefficient cars. Poor people, especially, tend to spend relatively more of their income on gas.
So when the price of gas goes up 95% (as it did from Jan-2006 to Jun-2008), and you have an older car and above-average commute -- you may have just taken a 10%-plus pay cut, when you may have been living hand-to-mouth already. Such people are honest about higher gas prices "killing them".
http://www.nytimes.com/interactive/2008/06/09/business/20080...
I think I was reflexively lashing out against some people I know that constantly complain about gas, yet choose to drive large trucks and definitely aren't struggling to make ends meet. For them I suppose it's just another topic for small talk, much like the weather.
Edit: why the downvote? Doesn't it make sense that those who are vocal about how gas prices are killing them are those who spend _way more_ than the 'average consumer unit'?
If gas represents 20% of your income instead of 5%, you are much more likely to complain when prices go up. This will be the case for people who make less than average, have long commutes and older cars.
That's only counting direct expenditures. Gas/oil is an expense for almost every other cost as well, especially food.