This friendship will have a big effect on your buddy, but it might not be the one they would have hoped for. They're discovering their life path and destiny; during the course of your friendship they'll strive toward graduating to a new level in their life, toward finding their path and following it. But they'll find that their pursuit conflicts with yours.
That shouldn't be a problem in a friendship, but you have a very strong idea of where you need to go in life, and you'll probably try to push your own ways onto your pal. But what's right for you won't be right for them, as hard as that will be for you to accept. You might have some very strong opinions (which you could forget are just opinions!) about where they're headed in life, and you'll react strongly against any moves they make in that direction -- which could actually illuminate that this is, in fact, the right direction for them to follow. Why don't you learn to accept your differences and encourage each other along your rightful path?