We are far from the first generation to have looked at the state of science and postulated that we can significantly extend human life span through some specific means - but we are the first generation to have possession of the necessary scientific knowledge to be correct in our evaluation. That we have this knowledge is why you can't just look at the long history of predictions of longevity and say "we're just another generation that will be disappointed - it's all more of the same." The past is a great place to look if you want to predict the future of politics, but a terrible resource for predicting the future of technology. There is an enormous difference between the state of life science of today and the nascent biotechnology of the 1970s and advocates like Timothy Leary - and not to mention the science of the early 20th century as is referenced in this article: "It might seem as if a magic [longevity-enhancing] pill isn't so far off. But before we get too cheery about the prospects for these discoveries, it's useful to be reminded of the many longevity 'breakthroughs' that have come and gone in the past. One such potential advance was hailed in the November 1929 issue of Technology Review, in an essay called 'Forestalling Death: The Cow's Contribution to Human Longevity' ... In the previous 125 years, Tobey observed, average life span had risen from the low 30s to the upper 50s. This was primarily due to reductions in infectious disease and in the infant death rate ... It wasn't enough to simply reduce a threat such as infectious disease - it was imperative that we find something we could add to our lives, or maybe simply increase our intake of something we were already consuming. He felt recent research might have uncovered just such a substance. ... He pointed to recent experiments at Columbia University, wherein one set of rats had been given an 'adequate diet' of one-sixth dried whole milk and five-sixths whole wheat. An 'optimal diet' group, meanwhile, received double the milk and less wheat. The average duration of life was almost exactly ten percent greater in those subjects receiving the optimal diet ... Is it possible that we have had the fountain of youth within our grasp throughout the ages that man has been seeking this liquid phantasm? Milk has always been recognized as the one most nearly perfect food ... but apparently it possesses hitherto undreamed of virtues." And so on: the end result is more of the oral fixation that seems to so dominate our culture - in the popular imagination everything of significance must be something that we put in our mouths and consume. Most important medicine, of course, is nothing of the sort.