I've never been the biggest fan of Star Wars. I certainly like most of the movies, and the idea of the universe, I've just never considered myself a super fan. I've been playing the table top RPG Edge of the Empire, as well as reading the latest comics, so I've found myself thinking about the universe a lot lately.
Things are weird in the universe, especially in the original trilogy, technology is pretty contemporary to what they had in the 70s. There are exceptions, of course, like significantly cheaper and more reliable robotics along with advanced AI to drive them, cheap and easy space travel including FTL, blasters and light sabers. At the same time, many things are incredibly low tech by our standards. They just don't seem to have an concept of computer networking, let alone wireless networking. Anytime a droid wants to access data from another system, it has to make a physical connection. A friend of mine likes to point out that it's ridiculous that the standard blaster rifle doesn't seem to have an automatic fire.
Then you've got space wizards, and a bunch of sentient races that mostly cohabitate in the same cities.
Space wizards are what I want to talk about though. When we first find out about the Jedi in A New Hope, we're told that most people think they're myths and legend, probably just charlatans, if they were real at all. This makes a lot of sense if Jedi are really rare, maybe there just weren't that many of them to begin with, or if there were a lot at some point, maybe their numbers were just on the decline until Obi Wan and Darth Vader were part of the last handful of them.
Instead, when we got the prequel movies, we were shown a world that heavily relies on the Jedi. They don't seem to have an official place in the Republic's structure, but the Jedi council heavily influences the senate, and takes requests from them to dispatch space wizards to areas of conflict. There is enough infrastructure around the Jedi that they have a system where they can identify force sensitive children early, and indoctrinate them into the jedi order.
Jedi are friggin' everywhere, until pretty much the exact day that Luke and Leia are born. They're all killed at once, and Palpatine transforms the Republic into the Empire. The thing that's funny about this is that it gives us a pretty precise measurement for the time between movies. Luke Skywalker is barely an adult, he seems like he might be 18, but could be even younger than that. That means that the Galaxy Far Far Away has had about 20 years to forget that space wizards were not only a major part of the the governing body, as well as the largest war that anyone has seen in a long time, they also start to think that they were never real in the first place. That seems pretty unrealistic to me, but maybe if the empire made a big propaganda push, that could sway enough people that at least the majority of the public think that way.
This further starts to fall apart when you start looking at life expectancy of the various races. This is where Star Wars really starts to feel like Lord of the Rings, because just about every alien race out there lives substantially longer than humans. Yoda lives to be seven hundred years old, Wookies also live for a pretty long time, Chewbacca is fighting fit adult in Revenge of the Sith, hangs out with Yoda, is just starting to get grey fur by the time of Force Awakens, which is maybe 60-70 years later.
With lifespans of that length, the idea that people "forgot" about the jedi becomes harder and harder to swallow. In Force Awakens, we're introduced to Maz Kanata, who has run her establishment for around a thousand years! Who knows how long she was alive before she bought the building, but she certainly knows that space wizards walk among us.
There is certainly a lot to dislike about the prequel movies, and I'm sure you can find a number of people more eloquent than I who have cataloged all of the reasons to hate them, this is just the thing that's always really bugged me.