Matthew Simmons has written about it:

Limits to Growth Revisited

There were several reasons the oil lasted longer than expected.  Conservation.  Recession.  But Simmons argues the biggest "mistake" made was that the analysts were assuming that the rest of the world would catch up to the U.S. standard of living.  (We were such idealists back then.)  

Instead, the gap between the haves and the have-nots widened into a chasm.  Rather than a car in every garage, we ended up with two SUVs, a boat, an ATV, and a riding mower in American garages, while most of the rest of the world is lucky to have a bike.

Between 1970 and 1980 the geophysicists realised that you could use the difference between "shake" and "pressure" waves to detect fluids. Shake waves only go through solids, but pressure waves go through fluids, too, like, say, oil or gas.
By 1980 even the oil company executives realised that oil prices would collapse during the 80s due to increased supplies, which is why they were all buying electronics and coal and mining companies.
But Carter didn't get the word, so no go on reelection.

Why are you here, Glener? Do you think oil has 50 or 100 years of producing as much as 'we' want? I don't remember Carter saying oil will run out by the end of the 80s. But he proposed a set of policies that would gradually eliminate US dependence on imported oil. Was that a wise or stupid strategy? What's yours? Are you wiser or more stupid than Carter? How about 25 years hence, would you be more prescient then than Carter was in 1979?

The costs of policy are wider than you perceive. If the US had eliminated dependence on foreign oil a decade or more ago... would 9/11 have happened? would the US have spent immense amounts of military money in Afghanistan and Iraq? would the price of oil have increased as much?