Maybe it was the kind and quality of the corn and beans, and how they were cooked.

Also, the less often one eats, and the less seasoned or sweetened (good tasting) food one eats, the better things taste. So, the corn and beans may taste better if it was the only thing you have to eat after not eating all day.

No, I've been that way ever since I was a kid.  I was once at a family reunion and someone brought a green bean casserole.  I thought it was one of the nastiest things I'd ever seen.  The smell is a lot of it.  The smell of hot chlorophyll is nauseating to me.  The corn itself is fine.

As I said, everyone's tastes are different.

Canned turnip greens is horrible. Any fresh green from the garden is so much better, even if too spicy or bitter for my liking. I used to hate beets (canned from the store) but fresh cooked are pleasant. Not everything grown in the garden is good, but that's due to varying growing conditions.

Again, that's where people's tastes differ.  I am very fond of Glory Foods turnip greens and mixed greens, they are heavily seasoned in Southern "soul food" fashion (don't knock it till you've tried it).  For some reason they don't have that hot chlorophyll odor to them, must be all the iron as well as the spices.

Mayonnaise is my kryptonite.  I got sick on it one time and can't even stand the sight of it.  Yet in the DC area, getting a hamburger without mayonnaise takes an act of Congress (probably a fitting metaphor), folks up there just think of it as an intrinsic part of the sandwich, and you have to clobber them over the head to get them to omit it.  Some dietary habits are regional.  Might be a Chesapeake Bay thing or something.