This "loss" and "all" talk is too binary. The real world is all analog spectrum.

Aside from "lose", there are also cultural outlook problems WRT what "knowing" means, not to mention what "power" is. And then there's topics of "education" and "wisdom"...

For example, although this sounds like a joke, its actually serious: Consider a population 200 years ago the same size as HN this afternoon trying to build a barn, a classic barn raising party. Now consider the population of HN, today, starting five minutes from now, trying to host a barn raising party presumably via twitter and flash mobs and watching youtube videos while sipping lattes at the local makerspace. For all intents and purposes we have lost the 1800s technology of community barn raising. At least we as defined as HN participants.

In theory, in about as much time as it takes a child to grow up, HN as a team, could successfully get our act together and git commit 2.0 of barn-1820. In practice it would be easier / quicker / more reliable to do the ole ageism thing and grow a new batch of fresh teenagers to build the barn. Less old ideas in the way.

That's how you lose a technology for all practical purposes.

For another example, its pretty easy to take my backyard, and industrially mechanically farm corn on it. People do this all the time a couple miles away. On the other hand we've pretty well lost the technology of growing a couple rows of carrots at a backyard scale, if you define "we" as more than single digit percentage.