Hey there! Let me help you out since you seem to be confused.

Some people enjoy bottoming. Some people enjoy topping. Some people enjoy both. Some people feel that their dick size would make them a bad top. Some people feel that their body size would make them an unattractive bottom. Some people have had things in their butt and it hurt more than it felt good. Lets remember that, medically speaking, sticking anything up your butt is not healthy. As such, if someone doesnt want to put something up their butt, that desicion should be respected and not scrutinized under ideas of immaturity, naivety, or otherwise. If someone says to me, "i dont like my neck being touched," I'm not going to think that he hasnt tried it, or tried it once but the person didnt do it right. I'm not going to question that desicion. I'm going to listen and say "ok."

There are a thousand reasons why people are tops and bottoms. Being verse does not make you better, more sophisticated, or otherwise. You also cant diagnose why a bottom is a bottom or a top is a top.