Lets see...
Ketchup - I guess as a kid I loved condiments. Now this just is too salty for me to enjoy.
Beer - I know, I'm a communist. But it tastes like crap. The fact that it looks like stale urine doesn't help, either.
And finally...
Lobster - I tried to prepare one once. It fought me when I tossed it into a pot of boiling water. I had to hold the lid down. After a while it sounded like it was squealing. It was seriously a traumatic moment for me. I can never eat lobster again.