Why don't people have meaningful friendships after school

I'm a store manager at a convenience store. I have coworkers who have worked for me for years. I've known them through their breakups, their engagements, their children, their parents deaths. We have a cordial relationship but I've never met them outside of work, I've never even been in their homes.<br><br>I know a guy who I dated years ago, he had a massive crush on me, I've seen him change from a "nerd" to a "fuck boy", go through relationships like nothing, lose his Dad, start his career. I've never gone to his house, I've never even been in his car.<br><br>I've been friends with a girl since kindergarten. We were inseparable growing up, she was my partner in crime, she introduced me to the only guy I ever loved. I haven't seen her in years, I barely speak to her, I live 45 minutes away from her but I still don't see her.<br><br>I never understood...we as a human race...are equipped to have meaningful relationships...so why don't we?