What show did you find impressive back in the day, then realized later it was full of holes?

My experience with this tonight: when I was a kid I watched an episode of Columbo that was all about wine tasting and wineries. ("Any Old Port in a Storm" if you are curious.) It had Donald Pleasence as the suspect and Julie Harris as the secretary, two people I recognized from old movies. Anyway, the thing that made an impression on young me was the wine stuff. I knew nothing about wine (and still know about as much), but I could recognize the geek appeal: there are obscure rules and trivia, and the guy who knows the most wins. Columbo uses this against the suspect and proves the case.

So flash forward to now, going through a DVD collection and finding the episode. All the stuff I remember is there, plus a lot more - the murder is an allusion to Edgar Allen Poe! But the story itself is full of holes, the case is utterly impossible. No way could they have fooled the cops even briefly that the murder was an accident.

Now, it's still a great episode, just to watch these actors and characters. Peter Falk is always fun and I'd watch him in just about anything. But it's kind of jarring that this particular show that has stood in my mind for so long as The Cool Wine Geek Episode turns out to be complete bunk.

So, what TV episode, special or movie of beloved childhood memory did you later realize was nowhere near as good as the image you held of it?