I was the pickiest eater imaginable, until I was well into my teens. When I was five, I had to be put on a diet to gain weight and get some, ah fiber into my body. I distinctly remember my mom sort of shoving a banana down my throat, along with some really gross, thick chocolaty stuff, that I think was for constipation... I had been living on white bread and butter/milk for months. My stomach always hurt and I was seriously underweight. Then I went through a phase where I just gagged on everything, when I was about eight. The smell of tuna fish made me nauseous and I don't think I ate a vegetable or crunchy fruit until I was 16.
Now I eat everything. I think when I was in college, I started eating more fruits and vegetables and ethnic stuff. My dad was in the wholesale food business at that time, and I often got to go to restaurant openings. Also, my mom always was an outstanding cook. There were never any mixes or prepared foods in my house. I learned to cook just from watching her.
I have never had bad "guest" experiences. I did a have a couple of friends who ate virtually nothing, because that was the only way they could maintain their weight. This was a long time ago; I do remember one sort of annoying me when she pushed the food around on her plate at a holiday dinner.
I had one kid who was just like me. He was in the 5th % for weight growing up. In some of the pictures from when he was around 3, he looks like a concentration camp survivor. Guess what? When got to high school, he had a lot of friends who were vegetarian. They exposed him to lots of stuff/restaurants and now he eats just about any ethnic cuisine. Still doesn't like crunchy veggies or fruit, though.