"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.