I think by now you could start an entire collection of retrofuturistic ideas and expressions that at some point signified progress before falling out of fashion. What I think is interesting though is that sometimes expressions that were thought of as well and truly dead reappear or take on a changed meaning. Two examples:<p>The e- prefix. It used to be ubiquitous around I think the 90s, but then at some point must have gotten rapidly unpopular and basically vanished. The only place where it survived was in the term "email" as some sort of linguistic fossil. Though recently it seems to come back in terms like "e-commerce", "e-cigarette" or "e-paper".<p>Cyber-. I think the roots actually predate the computer age with the 19th century field of Cybernetics. From that it took on a strong role in 80s science fiction at the beginning of the internet with visions of augmented humans and livable virtual worlds. Then Gibson gave us the "cyberspace", which became mainstream and for some time described the actual internet - before at some point taking on a terribly stale and outdated feel like "information superhighway". But for some reason the prefix eventually reemerged with a different meaning and today seems to mostly refer to security or military matters with relation to the internet. I'm not sure how exactly this change of meaning happened.