Would it be okay for me to get a piercing, and why are so many opposed to piercings on 13-14 year olds?

I am a 13 year old female, and so you know what you are answering, I have pretty much an adult maturity level. I can definately be trusted by others who know me. I am a straight A+ student for the most part and consider myself very respectful and thoughtful. I have been doing research for a past 2 years now into care and possible problems, how to fix them and how to prevent them.I want this not to be popular or follow a trend, not for attention, not even really for expression( how can you really express feelings by a hole in your body? Tattoos, maybe but not this) This is what I want purely for aesthetic reasons. I know my tastes may change, but if they do I can take the piercings out. The same principle applies to jobs, careers, etc. I feel like scars won't matter because they will remind me of more fun, more youthful times in my life when I could do things like this. I also feel that no matter what, I will be comfortable in my skin. To give you a clue about my personality, I am the shy, semi anti-social type with somewhat odd, contradictory interests that doesn't give a hoot about it when people judge me, but I still try to stay respectful and not judge other people or be rude to them. Confidence is key. I would also, however, like to understand reasons why people would say no to a peircing. 'You're too young" is much too vague, IMO. I don't believe that it could be said that a person my age can't make their own decisions, either, because obviously they could make the decision that they wanted the piercing and are willing to endure that pain to get it. If the reason they want it is vain and impulsive, I get that some people would disagree with it. But why do so many people say no, even when it is evident that much thought has been put into a decision? Though piercings, especially facial ones, were not mainstream in the '60, '70, '80's per se, they are now. Please answer this question by RESPECTFULLY stating your opinions as clearly as possible. I do not want my decision to be too biased, I don't want to get this piercing if the only opinion I hear is my own. Try to answer as thoroughly as you can, and due to the serious nature of this decision, all answers whether in my favor or not, will be shown to my parents and reviewed extensively. Thank You and God Bless.