I have a grandson that only ate Mac & Cheese, Chicken Fingers and Taco's with just meat and cheese until he was 18 and started noticing girls and decided that if he was going to do any dating he had better expand his culinary tastes. I also have a granddaughter that would eat different things differently. Pancakes, plain no butter, syrup or any other topping, Spaghetti plain, no sauce, no butter, just cooked pasta. Cereal dry only. There were other things as well but to numerous to remember. That lasted until she was around 16 and also decided she needed to expand the old taste buds.
Things have changed, I guess. When I was growing up and when my kids were growing up, they had a choice, eat what was cooked or go without. We were to busy trying to survive to make special meals for anyone. Your choices were only what was placed in front of you, nothing else. I don't remember having more then one problem with that and that was when my oldest decided that she wouldn't eat peas. We had a useless confrontation over it that nobody won! She continued to not eat them until one day, back when we had a small garden out back, I was sitting there eating peas directly out of the pods and she thought that was interesting and tried one. Peas have been her favorite since that day. The only time that I broke that rule for them was when their mother tried to feed them Liver and Onions and that is something that I won't eat. I got in trouble for not backing her on that item, but I couldn't see myself forcing my kids to eat something that I found disgusting. My wife used to eat things that were just odd to me. The one that I did try was cow tongue. I choked it down a couple of times before I just requested that not be included on any future menus. When we had that I wasn't sure if I was licking my lips or my dinner was. I am usually up for anything once except slimy stuff like oysters and snail. I've even tried pigs ears which, not surprisingly is mostly cartilage and rubbery like calamari and rubber bands. Certainly not a culinary delight.