Think about it. We're used to progressing through time and coming out with a more convenient (albeit less quality) way of life. Microwaves, DVDs, yadda yadda. But have we ever gone, "Oops, we can't do this any more, you're going to have to sacrifice?" I mean, cars have given us freedom and in cities people are often encouraged to talk public transit, which is, IMO, a step back in convenience. Any others?