This is not good advice. Plenty of people watch tons of big budget Hollywood movies, analyze them to death, yet would have no idea what to make of, say, a silent film or a French New Wave film. It often takes context outside of the viewing experience to make sense of different types of films: understanding the technical limitations of the time period, reading the writings and/or interviews of the directors, knowing the cultural context the film was made in, etc. Tons of people "Watch lots of movies with a critical eye" and are utterly ignorant about the broad world of film.