The decline in gasoline prices over the past four months has been sharp and surprising. But for Americans wondering why their family budgets still feel strained, part of the answer is almost as surprising:

Gas is not actually that cheap, at least not when compared with its level for much of the last 30 years.

At $2.03 a gallon — its current nationwide average — a gallon of gas is still more expensive than nearly anytime in the 1990s, after adjusting for general inflation. Over a 17-year stretch from the start of 1986 to the end of 2002, the real price of gas averaged just $1.87.

That era of cheap gas is easy to forget. Yet it offers a couple of important lessons about two of today’s biggest economic (and political) issues: climate change and the great wage slowdown.

Political leaders — from President Obama and Hillary Clinton to Jeb Bush and Scott Walker — have been signaling in recent weeks that they consider the wage slowdown to be the country’s most pressing issue. And it’s clear that energy plays an important role in it. The beginning of the wage slowdown roughly coincides with the end of the era of cheap gas, which is no coincidence. Energy costs are a major expense for most middle-class and poor families, taking a chunk out of their real (that is, inflation-adjusted) wages.