Hey, I´ve just seen, you´re only 17 years old! I don´t mean to feel better, because I´m older than you are (because being older is certainly no privilege), but believe me: Your mind will change and YOU will change!
I´m nearly in my mid-twenties now, and I know lots of people around my person, who changed their opinions, especially on stuff like tattoos or piercings, even if you´re definitely not old, when you´re 23 or 25.
You simply develop. And tattoos have nothing to do with rebellion or anything like that.
Wait one or two more years, if you still want to have it, go for it. But in my opinion you should keep COB in your mind and soul, but not on your skin. Think of it!