There's a lot of truth to this. In his seminal work "The Structure of Scientific Revolutions" Thomas Kuhn pointed out that paradigm shifts (a term he coined) do

There's a lot of truth to this. In his seminal work "The Structure of Scientific Revolutions" Thomas Kuhn pointed out that paradigm shifts (a term he coined) don't happen because lots of people who used to think one way start thinking another. Rather, a very select few who are capable of changing their minds start thinking differently, providing a guide around which new entrants can form their own opinions. This continues until the advocates for the displaced view have reduced themselves to a minority by literally dying off. In other words, you never see a true paradigm shift take place in a single generation. Two or three is the more realistic norm.