Two things:
1) Mt. Dew. I had a bad experience as a small child with Mt. Dew. It was my first time drinking it and I think I was ~3 or 4 years old. We were on vacation in Florida, fishing off a pier. Someone next to me had a big catch and was struggeling to reel it in. It was a big battle. The end result: he hooked a stingray and during the battle, the hook nearly cut the stingray in half with blood and other things spilling out as it was pulled from the water. I cannot drink Mt. Dew anymore without feeling queezy. Psychologists say bad experiences do this to people.
2) Just this January I took a trip to Japan for the first time. I detest sea food, so I knew I was going to be miserable. Most of the food was awful tasting, yet tolerable. Except for one item: raw squid cap rolled up into a little flower shape. The nasty fish taste was present - and very strong. The squid was so slimy, it oozed around my mouth. It was so rubbery (like eating leather) that my teeth couldn't cut it. It took about 3-5 minutes to swallow that one bite. The thought of rever eating more squid makes me sick.