You're seeking your rightful path in life, and your friend will really want to help you find it -- by advising you, challenging you and pushing you to be more like them! But the strength they've built up was in response to situations that you won't really relate to; you have your own battles to fight and insecurities to face down. You need to do what's right for you, but your buddy will have a hard time relating to those goals.
They could even start to act like an authority figure in your life instead of just a companion. Their advice won't hit home for you, and the way they'll try to force it on you, acting as if you're messing up if you don't follow their example, will really get on your nerves. You'll have to stay strong and true to yourself, and not cave in to your friend's influence. If you do give in, it may mean you're just not ready yet to follow your true path.