I remember when gas was 25 cents a gallon. And at that time you could buy a loaf of bread or a pack of cigarettes for 25 cents. In constant dollars gas isn't that much more expensive. I also remember filling my tank up 1998 for 99 cents a gallon.
Compared to the 99 cents a gallon in 1999, prices have gone up big time in constant value. The price index has not doubled since then, yet the price of gasoline has more than doubled.
The thing to keep in mind, though, is that the price of oil was unusually low in 1999. Oil companies were losing money. Anytime you have an industry losing money, you know that the price is ultimately going to go up. Companies in that industry are going to shut down capacity because it's not profitable, and as they do, the price will rise.
We spend more money on bottled water than gas. I go to the carry out & pick up about 16 oz of water for about $1.19. That would make that water about $9.52/gallon (if I'm doing my math right)!