Somewhat unrelated, but - is it just me or do other people notice too, that whenever a major university publishes course materials online, the instructors there are normally very young? It wasn't like that a while ago, e.g. when Coursera started, or it is not like that if you look at older MIT videos.
Does it reflect university teachers getting younger? Or younger teachers tend to give more effort to putting everything online? Or did my perception change with age?