I hated cilantro the first few times I had it (early 90s) and then got addicted to it. Genetics be damned. I usually have a bunch in the drawer at any given time, and if it doesn’t go with anything I’m making for dinner, then I just add to my lunch sandwiches, soup, or salad.
I, too, didn’t like tomatoes much growing up. That included spaghetti sauce and the like. (Part of this was due to a horrible stomach flu incident when I was 5, but I digress). Then I discovered I didn’t mind raw tomatoes if you rinsed the seeds out, and now I’ll eat tomatoes pretty much any old way. If they’re at all better than the generic supermarket variety, nothing beats a tomato and mayo on toast, seeds and all.
Fish and eggs. I blame Mom for this one. She didn’t like them, so never cooked them. So I assumed I didn’t much like them, either, other then fried smelt and eggs for breakfast at Grandma’s house every now and then, fried walleye or roughy over a campstove if Dad caught it, and shrimp. I don’t think I even tried tuna salad till I was a teenager, but I liked it immediately. Same with catfish–never had any till college, but my dorm fried up messes of it on Fridays and I was hooked. I’ve since branched out to most seafood (love eel and octopus, wish it were more available), and will try any fish, though I don’t go out of my way for it in general. I also never tried sushi till about a decade ago. It’s pretty good. Though in the Midwest, unless I head into Chicago, I find that the “creative” junky sushi are often a better bet than the simple nigiri-type. Mmm, fried soft-shell crab roll. Sea urchin can F right off, however.
As for eggs…well, as long as the yolk taste isn’t overpowering, I’ll be happy to cook and/or eat. I’ll devour my weight in good egg salad or devilled eggs in no time flat. It’s weird, because I love a strongly-flavored yellow mayonnaise, but still can’t eat more than a couple bites of custard or derivative (pie, flan, etc.) if it tastes of egg.
Speaking of eggs…eggplant. Irrational dislike as a kid. I still have little use for this vegetable, since I find it tastes of absolutely nothing, but I’ll eat it. I usually sub zucchini in recipes, though (much to my husband’s dismay, as he grew up with a lot of Sicilian cooking) since it at least has a flavor.
ETA: Kind of a weird one. Ketchup. I find myself craving it every now and then over the past few years, whereas I’d never touch it before (unless it came on a hamburger or something). I have no idea.