I don't want to drift away from my brothers or parents as i get older?

I'm 15 years old (male). My family is everything to me. My brothers (17 and 19) are my role models and my parents the best you could ask for. However, the older i get, the more i feel like I am going to drift away from them. my oldest brother is moving away to become a policeman soon, and before i know it my other brother will be moving as well. Eventually, I'll probably move away for university or a girlfriend. I hate the idea of change on this level. I don;'t want to drift apart from my brothers or my paretns. I was wondering if anyone had been through this or if anyone had some advice on how to cope with it. Thanks