Mankiw cites the following as why people hate high gas prices, from an econ professor at Duke U:
"if I stood next to the yogurt case in the supermarket for five minutes every week with nothing to do but stare at the price, I would also know how much it has gone up — and I might become outraged when yogurt passed the $2 mark."
I don't quite think that's it. For one, gas has next to zero quality differential. Unlike a yogurt tub from Wal-mart versus a yogurt from Trader Joe's or whatnot which has a huge quality differential in terms of perceived quality/health of the item and in terms of quality of service, a gas station serves a fairly uniform undifferentiated product, as well as a fairly uniform undifferentiated service. As such, all competition, and therefore all cognitive recognition by the consumer, is done at the price level. So, it doesn't matter how long they wait in a line. Further, because gas is a a necessity for most people, people see the price every week regardless of having to wait in line. Because price is so pre-eminent and reported pretty much every day in the media, people know roughly that gas is "high," and are still going to be outraged. Having to wait in line just adds insult to injury.