Getting older has one redeeming characteristic: it affords you a platform from which to look backwards and see milestones and key concepts, the significance of which were not nearly so clear at the time. We engineers design things; that necessarily means we try to envision the future and then try to realize that vision. But our collective ability to predict the future has never really been all that hot. (Any of you who bought Netscape, Yahoo, eBay or Google at the right time and are now ridiculously wealthy, you can stop reading, this doesn't apply to you.) Still, we must try. It's been said that the best predictor of the future is the past. So the occasion of Carnegie-Mellon's Computer Science Department's 50th anniversary seems a great time to look backwards, extract the lessons of our industry for the past few decades, and see what patterns emerge and what they might tell us about our technological future.