He's too young

I can feel it. But he won't see it the way I do. There is so much he has yet to do. But he doesn't see things the way that I do. He accuses me of being snotty, sitting on my high horse. That's not how I intend on behaving. The fact is I HAVE experienced more than he has. I am older...and while not as wise as I wish...wiser just the same.
He'll wake up one day, and realize that this was not what he wanted. That he has bitten off too much, more than he could ever chew. Then what??? What becomes of all we've built and worked so hard to be?
He'll leave and I'll be alone without my best friend, without my companion.
Better to just cut ties now??? While hearts are still in tact? I wish I knew...but I do know, He is too young!