I didn't hate much; I was the kid who'd try anything (as opposed to my siblings; one brother spent years living on noodles and weiners, the other did likewise with grilled cheese sandwiches, and my sister was always "picky").
The few things I can really remember hating: brussels sprouts, kohlrabi, and spinach. I can still live with or without kohlrabi, but the brussels sprouts and spinach -- NOT cooked by my mother, they're wonderful! My mother believes that if "something is cooked it should be COOKED!" That is, grey and limp. She hates all kinds of raw vegetables; the only vegetable salads I EVER ate growing up were marinated tomato, and German cucumber-sour cream. I love salad! I love vegetables! And to think I never knew!
Okay, those weren't the only salads. We also had egg salad and potato salad. I didn't like those, either. Or so I thought.
Actually, what I didn't like -- and still loathe -- was Miracle Whip.
Plus, I didn't discover garlic until my twenties. Garlic makes my mother's stomach disagree with her. Even now, she glares suspiciously at anything I cook for her: "There's garlic in this! Isn't there! I can taste it!"
No, I swear, not a single morsel. Not even a bit of garlic powder. I must admit, though, when I first found the Miracle of Allium sativum, my philosophy was "Why use one clove when ten will do?"