Cream.

As a kid, we owned a village shop in the early 1980s that used to sell clotted cream in big open trays. We'd eat what didn't get sold - until one day I was given some that was very off. I was violently sick and stayed well clear of it for forty years. Tried it again recently in my mid fifties and it's quite nice.

Also fish - hated the taste when I was younger, but tried it at middle age and quite like it now. Just a change of taste.