Cueva de las manos source (Public domain)
Over the course of history, you can see that cultures change. Some believes that people held in one century - held so deeply that to even doubt them would get you laughed at - were completly forgotten one century later. When one man in the 15th century didn't believe in a certain thing, he was called crazy and when one man still believed the same thing in the 21st century, he was called crazy.
Styles change, and what once was something people spent hugh amounts of money on, is now something everyone would be ashamed of.
Things you once weren't allowed to do, you now get in troule for not doing and things you once were expected to do, you now get in trouble for doing.
What was once progressiv is now hopelessly old fashioned and what was once fringe is now mainstream, whereas what was once mainstream can now only be found in small niche - subcultures.
And this isn't just a dichotomy between our time and "the past", but between any two time periods.
But through all this, there are also a lot of simularities. Almost always, the old generation thought the youth was lazy - I think you can find egyptian papyrii about it. Always people wondered what the best life could be - allthough the answers were different, the question always was the same.
But I want to mention one other thing, that I believe hasn't changed. A sentence that even our ancestors in the stoneage said all the time: "I miss the good old days!"
