I'm not a super picky eater, but there are some foods I won't touch.
Pickles, kimchi, and beets taste awful. Cottage cheese is a sensory nightmare. I don't think I'll ever attempt oysters again.
I hate how prevalent pickles are in American restaurants. Seems like I have to ask for no pickles in every new place, and half the time they'll have pickles anyway, or they'll include pickles in dishes that have no business including pickles and I wouldn't think to ask for them to be excluded. If I pick them off I can still taste the pickle juices, and it ruins the food. The sandwich and burger places think they're so fancy for including a pickle spear in the plating, and it's a crapshoot whether they keep it isolated off to the side or drape it across the food where it can contaminate everything. Miserable.
Pickled jalapeños, lettuce, and mustard are on thin ice.
I don't like ranch dressing or ketchup, but I'll only grumble a bit if I find them in my food.
I'll try anything once, and I do go back to foods I hate every now and then to see if my tastes change. I used to have a hard aversion to seltzer water, sour cream, and hoppy beers like IPAs, but I've come around on them. I have a much better appreciation now for bitter and sour flavors than I did as a kid.
Still. Fuck pickles.