I don't take it lightly either. Sure, we all make mistakes and have flaws, but friendships in my opinion always take time and depth, and I'm realizing more and more that sometimes having some or even a lot of things in common isn't ever enough. It should be a bond akin to family, as if that person is your brother or sister. And of course, it's impossible to have everybody as a close friend, and I'm not trying to say that there's anything wrong with casual friends or acquaintances either. I'm merely just speaking for myself.