I have several friends with this strong preference for only eating certain foods - hamburgers, chicken fingers, french fries, noodles, pizza, vanilla ice cream, goldfish crackers - and they're all men, oddly enough, and all over the age of 25. One of them is 71.
It's so hard for me to understand, because I have a very adventurous palate, as does my sister, and our parents gave us a wide and varied spread of foods from a very early age (sushi, babaghanoush, caviar, tagine, etc) so we learned very early to find new tastes and textures exciting and satisfying.
To each their own, I guess.
I do think that someone of a adult age who is only eating a few noodles at a time may want to consider talking to someone about a possible eating disorder, but I'm not a nutritionist or a psychologist and I really don't know when pickiness shades over into "disordered eating" - as long as someone is getting the nourishment they need, I'm thinking it's probably fine?
ETA: I do have a few foods that I don't like and won't eat - one of them is okra, which I tasted for the first time at Port Orleans Resort in 1991. Someone handed me something fried, I bit into it, it was SLIMY AND HORRIBLE, I spit it out, and that's where I learned about okra and that I hate it.