Imagine you're a kid in US in the 60's, watching a lot of your favorite Tv shows and movies. Ten years lather you have a son, and have a idea to introduce him to the universe of thing you consume when you was a kid. Doing it you are creating a sense of nostalgia in the next generation, and this from the entertainment industry it's crucial, because if you have a nation thinking in the "good times " the only thing you as creator must do is rescue the idea from a movie, TV show, videogame, music, and using it form crate a new product. One big exemple this is the new Steven Spielberg movie Ready Player one, and the marvel's movie Guardians of the galaxy, the both use the nostalgia to make money, and sorry i think it is amazing.
If you know what kind of nostalgia the people are interested, you know how to make a product form they, and today, this nostalgia is the 80's, in ten years it will be the 90's and the 2000. So if you like to work making movies, you have to, right now , start studying the 90's.
you understand ?