Truth is, he doesn’t need her in life.
In fact, nobody really, really needs anyone in their life. If they know enough, they can live their life just fine, with all the goals, all the paths ahead of them.
But because having her in life makes his life better, richer, brighter; because it makes the world feel a little less lonely; because it gives him a little more sense of security; because it gives him just another good thing to look forward to each day
Because of all these, he wants her in life
It’s not that she completes him. He might well be incomplete, but that wouldn’t be because he is missing a piece that is her. Like her, he is a whole being.
But being aware of it, who the hell would reject a better life?