I Don't Understand: My Best Friend and "We're Not Mature Enough"

Wow, what just happened here on my couch. *A* I think intently came over to discuss what's going to happen with the living situation. He said that he's not sure what to do since he doesn't want a relationship that it might not work well living together. I said, of course that wouldn't be good, so let's just be together already. He's said that he's not ready for a relationship.

Not ready? I've known him for 17 years. We dated for several of those years. We've both dated other people. How can he not be ready? He said: We're not mature enough.

I said, "what does that mean? You're not mature enough? You're not ready?"

*A*: You know, settling down, having a baby.

Me: Who said that's what I'm looking for? Couldn't we just be together a little bit? Be best friends and physical and live together?

*A*: That never works out.

Blah blah. Anyway, so part of him is caring about our friendship, but part of him is being afraid. I don't know what I'm supposed to do with this. He was super cuddly with me afterwards as if he was torn by what he was saying. When he left he told me: You know that I love you right?