For the most part, someone who's always with somebody else doesn't grow personally as much as someone who's on their own a lot.
And with that being said, I want to say thank you for having to make a decision of parting ways with my then best friend some 8 years ago. I've naturally become more of a loner since, and even though it wasn't easy at first, it allowed me a chance to really open up to the world. I'm not going to get into the details of this mess of a friendship, but let's just say it could be compared to being in an abusive relationship. Thank you, Y., for being in my life, and thank you for making me let go of you too.