You get married, and the thought of kids is terrifying. The loss of freedom, the sudden responsibility, the questions about money. After a few years the terror subsides– hey, this could be fun. Gotta start sometime. So you talk, you make plans, you dream. Then real life happens: you don’t just check a box and get a baby. Biology has a role, and it doesn’t always cooperate. So you wait and hope and pray and are disappointed. You read books and visit doctors and have well-meaning people say “The second you stop thinking about it!” Your perspective changes. You wonder how you ever thought this could be an inconvenience.

Then, it happens! The drug works, or you actually do stop thinking about it and it actually helps, or the agency calls with good news. And while you’re celebrating and laughing and picking out paint colors, it hits you: this could break my heart. One more person in whose life your own is now inextricably tied up. One more set of potential catastrophes that could turn your world upside down. One more subject of desperate prayers: “Please don’t let anything happen.”

After a near-infinite series of miracles, with cells dividing and heart beating and good movement (now? now? now?), this new gift arrives in your house. Before you’re home from the hospital, your world has changed. He has nothing to offer, makes incessant demands, and you have never loved anything so much in your life. You didn’t know you had the capacity to love like this.

Or to hurt like this. Because nothing is guaranteed. A normal pregnancy doesn’t guarantee a normal birth doesn’t guarantee a healthy baby doesn’t guarantee a healthy child. And even if they stay healthy and breathe all night (now? now? now?), one day they will hurt. Kids won’t play nice, or friends will move away, or you’ll move away, or the favorite toy will be lost, or the boyfriend will turn out to be a jerk. Their hearts will get broken. And in all likelihood they’ll break yours.

You add to the brood and the love you thought couldn’t get any bigger grows. It has room for more. More joy, more amazement, more laughter, and yes: more vulnerability. More possibilities of disaster. You would do anything, you would give everything you had in you, to protect these little people from the slightest hurt, from any little disappointment. But you can’t, and even if you could, you know you shouldn’t. Life will hand them beautiful and terrible things, so you try to prepare them for both.

You pray, you play, you discipline, you teach. You read the same book 12 times a week. You look forward to them being bigger, and then you cry because they’re getting bigger so fast and you miss the little them. It is so exhausting, so hard, so fun, so beautiful, so good. And you’ll never be done. One day they’ll leave, but the love will never stop, and the responsibility will never stop, and the vulnerability will never stop because the potential for heartbreak will never stop. Not in this world.

Worth it? You bet. This is the best kind of heartache there is.