Another, shorter way to look at the healthy, un-enmeshed marital life is:
Your wife should be the FROSTING . . . not the CAKE ITSELF. "I WANT you in my life, to add love and zest and passion to my own goals and passions, but I don't NEED you (or anyone else) to be happy."
That's not easy, and it's a journey I'm still trying to learn to walk, but that's sort of the idea. "Needy" isn't attractive in a man OR a woman, but it's especially not attractive in a man.