It's so random how people you never spoke to 20 years ago, for no reason other than being a stupid 17 year old and you're so consumed in your HS relationship, circle of friends that no one can penetrate, etc., can end up becoming great friends in adulthood. I had a similar situation with my friend Erin. I don't think we uttered a word to one another in HS, now we're close friends.
So for all of the HS students out there reading this (I'm sure there are droves of you out there - reading a 38 year old's random blatherings), talk to that person you wouldn't normally talk to. Don't be such an idiot..
One can never have too many good friends after all.