Looking back at 2018, how is it possible that just before our flourishing age of polymaths, it was not uncommon to see nonsense written like "Two hundred years ago, it was still possible for one person to be a leader in several different fields of inquiry. Today that is no longer the case."? I suggest it was a lack of situational awareness, about several issues.

About having time to excel. Artificial light capturing the night was a century past. Electrification and its labor saving was almost that. Few still farmed, and the cultural memory of the effort required had decayed. Commuting was common, and it was rare to be able to work during it. Consumer robotics and AI were still novelties. Major industries, both legal and illegal, were focused on encouraging people to squander their time. So there was no sense that people had more time available in the present than in the past, or might have more in the future.

About education. Education was still a wretched disaster, largely unchanged for centuries. Science content was particularly abysmal. There was some professional recognition of this (for example, chemistry education research characterizing high-school chemistry content as incoherent), but it was not widely appreciated. Popular focus was on the relative gap between "well" performing and poorly performing students. With no thought that future primary school students might soon be outperforming their present undergraduates. An educator might speak of nanometers as being "unimaginably small", rather than something played with in pre-K. The Internet was just old enough to be taken for granted, so on the eve of AR/VR mass deployment, people were mumbling the same nonsense as in decades past "I can't imagine these computers/internet/AR will have any noticeable effect on people's lives". Past progress, such as mass education regardless of class, was taken for granted. Such progress as was happening, such as attending to misconception ecologies, was not widely appreciated. They knew in the abstract that civilization advances by a teacher being able to pass on knowledge more easily then they themselves learned it. But having no sense of existing change, or of the backed up logjam of potential change, they were blindsided by the rate of change once the jam broke.

About science. Access to scientific knowledge was still highly circumscribed. Many journals were still not open access. Some research talks were on youtube, but it was still rare. Much insight into fields was still localized to conversations at conferences, and spread by word of mouth. Again, the world of paper journals and paper card catalogs was sufficiently past that there was no sense of the velocity of progress. "Non-scientists" contributing to science was seen as a novelty - the parents of a child with a rare disease becoming experts on it; or children with bees by chance asking an interesting question. Larger examples, such as community characterization of galaxies, were seen as isolated cases. Because hybrid AI-human systems, and computer supported cooperative work, were still in their infancy, and unappreciated. There was little sense that science had profoundly changed in the preceding half century, or would similarly change in the next.

So I suggest their blindness was rooted in a failure to understand their present, and a neglect of looking beyond it. A neglect of looking at their past, and thus of appreciating the velocity of change marked by their present. A failure to understand their present, and its defining constraints. And a neglect of reflecting on how those constraints were about to change. They lived in a bubble of time, peering myopically at the world, and thought themselves unmoving.