There is the bias you describe. There may also be a perception that leaving out old knowledge is somehow a "loss", not noticing or recognising the entrance of

There is the bias you describe. There may also be a perception that leaving out old knowledge is somehow a "loss", not noticing or recognising the entrance of new knowledge. When I studied, there wasn't room for learning git, and now CI pipelines are on the curriculum. And I may take learning git for granted because I know it. So yes, a lot of sample size = 1 mentality.