Here’s the other thing about kids being picky. It makes it especially hard on a child to be polite and accepting of new things when he is a guest if he has not been accustomed to accepting new things at home. Don’t let me mislead you. I hate turnips. I hate hate HATE brussels sprouts. (My computer does not know how to spell brussels.) I strongly dislike beets, mushrooms are icky, green pepper unless carefully prepared makes everything else also taste like cooked pepper and thus icky, rye and pumpernickel bread and yuck, banana pudding tastes like, well, banana, but waaaaay too much of it. Also I dislike sauerkraut.
There are foods I do not like. There are foods I do not run around preparing and force-feeding to myself and my family just because “it’s good for them!”
But I also know for a fact that I disliked tomatoes, asparagus, shrimp, fish in any form, green beans, lima beans, tomato soup, sweet potatoes, and a host of other items. I hated them then, I was made to eat them then, and now they are things that I like very much. I really like them, I really eat them. No forcing or unpleasantness involved. However, if I had not been given them repeatedly, in various incarnations (my mother is not cruel, nor stupid) until one was found that we all thought more palatable than others, I would not want them now under any form.
For example. My mother never tried to talk us into eating liver. She never tried, we never tried, and if you tried to give me liver today I would spit it out on your Pier 1 plate and say, “Ugh!! It’s disgusting! I can’t stand it!”