I saw TOS when I was 9-10 years old and it was mindblowingly good compared to almost anything else you could see on TV at the time in my backwater country.
Few years later I learned that this new series TNG will start airing and I was very excited. My disappointment was endless when I saw the pilot.
I strongly disliked the general production aesthetics and Enterprise-D looked just stupid compared to the iconic original/refit Enterprise of TOS era. The characters felt so empty compared to the old crew and the first season scripts weren’t so great, so I gave up on the series after seeing few episodes. This was in the early 90’s.
15 years later I saw a few episodes from the later seasons and to my surprise found that they were good. So I watched the entire series and enjoyed it. I still prefer TOS and love the new SNW, there’s something about the older era setting that just hits me in the feels.