I’m not sure if this can be categorically described as being a bad food experience, but earlier today I encountered something rather unexpected.
My wife and I took a jaunt over into the lovely town of Sonoma, where we walked around a bit and eventually stopped into a cool-looking Thai restaurant for lunch. After tea and appetizers, I ordered a spicy red curry seafood dish called Gang Dang, while Juanita ordered something with spinach, tofu, and peanut sauce.
A few minutes later, our meals arrived. I was really hungry, and it tasted delicious. I proceeded to chow down, impressed at the array of different sea creatures my lunch contained. Salmon, prawns, scallops, calamari, — but wait… what’s this?
There were some curly litle purple tentacles poking out from underneath some of the vegetables. I pulled them out, and to my surprise found that they were attached to a small octopus.

“Uhm… There’s an octopus in my food,” I whispered to my wife.

She rolled her eyes. Being far more cultured than me when it comes to eating weird asian foods, she calmly explained that it was totally normal.

“Just eat it,” she said, rather embarrassed that I’d mentioned it aloud. “It’s just like calamari. It’s not a big deal.”

I poked around and found three other octopuses of various sizes. They had been cooked whole, and were an exotic purplish color. It took me a few minutes to get used to the idea of eating the little guys, but I finally got over it. Juanita was right; they were just like calamari. Very rubbery, with no flavor. I couldn’t help but wonder: why do they even bother cooking such animals, if nobody actually enjoys them?
Even so, the food was great. We finished up and left, quite satisfied.

According to Wikipedia, the octopus is generally believed to be the most intelligent invertibrate animal. In a weird way, that kind of makes me feel bad for having four of them in my stomach.