As a writer, I understand the protective instinct that develops when it comes to your work. You’ve poured your heart and soul into this idea, and obviously it is important enough to devote your precious time to it. So when you show it to someone, be it a classmate or a friend, you may want to stand over that person’s shoulder and explain your thought process. You will want to answer questions and deflect criticism.
Here is the problem with that: If you publish your book, you are not going to follow around every single one of your readers to answer their questions as they arise. Nobody is going to sort out any confusion for them.
This brings me to today’s point. Your writing needs to speak for itself. It is so easy to get defensive when someone challenges a plot point. And sometimes it really is just a misunderstanding, and the reader just didn’t follow along. But that is the exception, not the rule. Generally, if someone has a question that requires clarification/explanation, then you have left something out of your story. Go back to you current draft, and edit, edit, edit.
There are no set-in-stone rules to being a writer. The point is to be creative, and explore a world you can paint with words. Depending on what you want to achieve with your writing, you may need to touch up your work. Be open to doing re-writes, and you can be successful.