The idea that we should all be living in gated communities with isolated commercial zones 10 miles away is a learned behavior. With a good PR campaign, people could also begin to learn that having access to amenities is desirable.

There are different kinds of people in this world. I live in Manhattan with shops all around me. People pay astronomical rent to live here so they can participate in this kind of lifestyle. Other people like to live in older-but-Smart-Growth-esque towns like Tenafly, NJ or some of the older Boston suburbs that have town centers with movie theaters, boutiques, coffee shops, and ice cream shops. Homes in these places are also expensive, presumably because people want to live there. So not only is the Smart Growth idea not new, but there are plenty of people in the U.S. who are desperate to live in just that environment. It's not a lost cause.

with $3 gas, people might be more willing to consider the efficacy of living near retailers - just not Walmart-esque big box retailers. Ithaca, NY (my touchstone for these sort of things) fought hard against a Walmart and kept its downtown district intact through the 1990s. Even the large supermarkets (I live Wegmans) are within 2 miles of downtown and require only a very short car ride to get groceries - for those without cars, they deliver for a nominal charge.
I agree, but there is a hell of a lot to unlearn.  Let me give you just one example:

When I was a kid, we still had the corner grocery store, and this was before the 7-11-ification of the small grocery stores.  Sure it cost a little more, but if all you needed was a loaf of bread or a can of soup, I could just hop on my bike and pick one up without anyone needing to get in a car.  Heck, it was even walking distance.

In some neighborhoods, you still see the houses that used to be the corner grocery.  The front door is on the corner of the house instead of the middle of one of the sides.

I have to admit though that even the large grocery stores have become 7-11-ified.  Entire aisles filled with potato chips.  The next aisle over is filled with sodas.  The next one over is a freezer case filled with frozen snacks and pre-made dinners.  It is pretty damn clear that not many people even make an attempt to cook any more.  Even the Asian market that I shop at has aisles filled with various jars of pre-made sauces, or bags of quick frozen dumplings - it still seems better than a regular grocery store.

For all of those folks who cannot even be bothered to pick up a quick-frozen dinner of some kind, there is always the drive through - even crappier fast food, and burning even more fuel in the process.  If that doesn't work then order a pizza and they deliver it to your home.

You could argue that people don't have the time any more to cook a proper meal, and to an extent it is true.  These days you have both parents working, so if you are coming home tired it is easier to pick up some take-out rather than go to work in front of a stove.

Now take this and multiply it by 10.  Virtually everything we buy these days involve getting in a car and going someplace.  Heck, virtually everything people think they need to do involves getting in a car and going someplace.