That actually means gas prices haven't gone up, or not by much. In the 20 years from 2001 to today, inflation roughly doubled everything

"Inflation" is a nebulous word, if you're referring to CPI, isn't oil price (via transportation, fertilizer costs) a major contributor to that increasing?

I'd expect a historic fuel price chart corrected for CPI to be roughly a horizontal line, because fuel prices majorly contribute to it.