It was actually very weird - I'd smell it, and remember the good taste, then have some and be quite startled how bad it seemed to me. (and again, other meats did not have that reaction). I have no idea if this is a matter of personal chemistry, a more intricate mental gymnastics than the one you propose, or is actually commonplace. To this day, the smell of KFC original recipe will make me salivate. (I once found an Indian place that had a veggie Pakora that tasted JUST LIKE THAT BATTER. Man I miss that)
For background: I went full vegetarian for 6 months in college, but stopped when I was seeing stars constantly. It's easy to get decent nutrition with a vegetarian diet, particularly as I'm not active, but microwaved rice and beans and mac n'cheese (my college diet) wasn't healthy enough. So I returned meat to my diet and that's when I found I didn't like red meat anymore. I imagine I could've taught myself to like it again, but I was content with the other meat options and had no more health issues. After a few years like this I noticed that a few foods (e.g. lettuce, baby spinach) that were previously on my "ick" list were now palatable, so I started dropping a meat a year, giving my taste and lifestyle time to adjust. After a few years of that, I was fully vegetarian, and my diet has expanded, though I still have a depressingly large "these foods don't taste good to me" list.
Why do I think pork is marginally than beef? I grew up in a rural-ish* area, and have a lower opinion of cows than pigs, in terms of intelligence and awareness. I similarly think a turkey is smarter than chicken, but we are talking literal bird brains at that point.
* rural-ish = a large town surrounded by farmland. State College, PA, for the curious.
You seem very self-aware, which I view as a rare and positive trait. So here's a question that I am genuinely curious about: in light of the fact that you said you remembered meat tasting good prior to becoming a vegetarian, do you believe that it is unpalatable to you now because it actually tastes bad (i.e. your brain actually no longer likes the taste), or is it the thoughts that you associate with meat (those that drove you to be a vegetarian in the first place - perhaps that a cow was killed for it, or its impact on the environment)?