By the time I went to see TPM in '99, I was 17 and super excited to see a new SW film on the big screen! Looking back, I was the same age as the target demographic for the OT. I expected the TPM to be good, and to look and feel like the originals, only it would tell a different part of the story. There would be new fight scenes that I could watch over and over again, new characters, new dialogue ... but still be a part of the OT family. That was the expectation I had walking into the theater in May 1999.
Unfortunately, TPM did not meet that expectation. I was not old enough, and could not accurately describe most of the film's problems like I can now, but needless to say everything felt wrong. The CGI ... why did everything look so much more advanced 30 or 40 years in the past? And why did the CGI look so fake? Thirty years later I can watch the OT and the practical effects look real, they never take me out of the movie, they only draw me in. But in TPM and the rest of prequels, the CGI immediately made me self-conscious that I was watching a video game film.
Later, Jar Jar popped up on screen and I suddenly felt embarrassed and uncomfortable to be sitting in the theater. Not only Jar Jar, but the Gungan boss, some of the other characters like the Trade Federation guys, they were so offensive and childishly depicted that I would have walked out of the theater if I could have. It no longer felt like I was watching Star Wars. And yet, there were still some things that carried over from the OT and appealed to me as a fan, so that by the end of the film, I talked myself into tempering my initial revulsion ... if only they had edited out Jar-Jar, the film would have been ok. Not nearly as good as the originals, but OK.
When I saw widespread criticism of Jar-Jar, I even convinced myself that Lucas would cut him from the VHS/DVD release!
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AOTC next came out in 2002, and I still hoped the rest of the PT would be good. Maybe TPM would just be the red-headed stepchild of the saga. Obviously, that didn't turn out to be the case, and AOTC was just as bad if not worse. By the time Yoda was spinning around like a flying monkey, I averted my eyes and no longer had any desire to finish watching what was on screen.
For me, that was the moment Star Wars died, when the wisest and most reserved character of the OT was turned into a cartoon.