There was this Facebook meme about the "25 highest-rated movies of all time." I thought that might be interesting to look at. Without telling you what actual films were judged on IMDb.com as the best in all of movie history, I invite you to consider the top 25 simply on the basis of the decade they were released in.
Silent Era: None
What this tells me, right away, is that the community of "critics" rating films on IMDb.com were mostly teenagers and young adults in the 1990s. These are the movies that blew them away back then, plus a few others they've seen on TV or read about as important. They are far enough in the past that they seem like giant mileposts in the history of cinema, but actually, they are of fairly recent vintage. Those rating the movies don't really know much about what came before their time. They know little of the ground-breaking movies of the early days, and nothing about the blockbusters of, say the 1930s (The Wizard of Oz, Gone With The Wind, Stagecoach, Mr. Smith Goes to Washington, and Good-bye, Mr. Chips are all from a single year in that decade).
So, this is an example of what C.S. Lewis called "chronological snobbery" -- meaning, the ignorance displayed by those who only know what they personally have experienced, and who take the ideas of their own age as the sum of all human wisdom.
Now for something more disturbing to think about: This is also how people make up their minds about politics, religion, philosophy, law, ethics. Most of what is trumpeted as the best of human thinking will always be whatever was current at a certain time in the speaker's life. It takes real study, real breadth of experience, to see beyond the Spirit of the Age and value things properly against the whole sweep of human thought and experience.
100% Pure Baloney