At the 34-year mark of his marriage, Tim Keller shared the following insight about his marriage:

Neither my wife nor I are particularly gender-stereotyped. Yet you get into marriage, and you find you see the world differently, and you see each other differently. She sees things in me I would never see. But she sees because she’s a different gender and she’s in close, and I see things in her, and I see things in the world.

After 34 years of conflict, of arguing, of head-butting, now every single day when I get out into the world and things happen to me, I have a split second to react. What am I going to say? What am I going to do? What am I going to think? For years, even halfway through my marriage, I only thought like a man, but now, after years and years of head-butting, here’s what happens.

Something happens, and for a split second, I not only know what I would do, what I would think, how I would respond, but I know how Kathy would think, and I know what Kathy would do. For a split second, because it’s so instilled in me, I have a choice. Which of these approaches would probably work better? You see, my wisdom portfolio has been permanently diversified. I’m a different person, and yet I’m me. I haven’t become more feminine. In fact, probably in many ways I’ve become more masculine as time has gone on.

What’s going on? She came into my life, and now I know who I am. I’ve become who I’m supposed to be only through the head-butting, only through having a person who’s like me, not me, opposite to me, in close.