"I'm having a baby, not a lobotomy," I said, feeling very clever as my friends chuckled. I was the first pregnant friend in our group, trying to reassure everyone, but especially myself, that despite the ever-expanding baby bump, inability to stay up past 10 pm, and the La Croix in my hand, nothing much was going to change.

I would have a baby, obviously, but I would remain pretty much the same.

I was uncomfortable at the idea of being "mom," picturing a lopsided mom bun, graham cracker crumbs ground into my Anthropologie sweaters, and being thought of as boring. I assumed my baby would comfortably slide into mine and my husband's lives while we remained us, with almost the same schedule and activities, plus a snuggly baby.

Then I found myself, a few days after a very long, decently-traumatizing labor, holding my teeny, tiny son, tears running down my face, so tired I could barely see straight.

My entire world had been turned inside out, shaken around, and given back to me, and I was trying to make sense of it on scant 30 minute stretches of sleep.

Everything had changed. I hadn't fully understood that through the birth of my child, my old self would have been left behind, sacrificed in the creation of this new life.

Instead, along with my new son, a new mother had been born, and we were both blinking in confusion at the light of day, startled to have left the warm and cozy embrace of what was before.

When he learned how to eat, I learned how to feed him. As he cried, I learned how to comfort him.

YouTube became my teacher, yoga videos replaced by tutorials on stroller folding frantically watched in parking lots, or baby burping how-tos hurriedly watched and rewatched. “Newborn baby day night confusion,” I googled. “Newborn baby breathing patterns?” “Newborn baby hates carseat?” “Newborn baby only sleeps on me?”

The young woman I was before had gone. Caught up in the relentless care of a newborn, I didn't notice her leaving until I was back at work 12 weeks later, sobbing at my desk, longing for my baby.

Everything had been utterly changed and I was wholly unprepared for it. I had read the books, but Bringing Up Bebe and Happiest Baby on the Block didn’t tell me that along with the new baby would be a new me.

And, to my surprise, as the weeks wore on, I stopped missing the old me and embraced the new me.

The old me was indecisive. The new me had to learn to make quick decisions with confidence.

The old me was worried she wasn't capable. The new me found that I could handle almost anything thrown at me (Crying! Diaper Blowouts! Stranded in a broken-down car with a 7-week-old!) even if there were some tears along the way.

The old me worried about making everyone happy and what everyone else thought. The new me focused on what her baby needed, and realized the freedom of letting the opinions of others go.

The old me had no idea how having a baby would turn my entire life and our priorities upside down. We've lived in Washington DC for 10 years, but are packing up to move back closer to family. Where I was full speed ahead in my career, I'm taking a step back to spend more time with my son.

And, to my pleasant surprise, embracing the new me—motherhood in all its messy, undone, baby-giggles glory—hasn’t entirely erased the old me.

I still appreciate thoughtful books, even if they’re read in fits and starts.

I still take pleasure in making delicious food, even if it might look like a slow-cooker meal and baby puree.

I haven’t quite gotten back to daily hot yoga, but there’s a lifetime for that.

When I was pregnant and contemplating changing everything for my baby I had only fear of change.

Instead, now I feel, through these difficulties and changes, I have found who I am at my core. And motherhood has revealed the woman I always wanted to be.

With the fear stripped away I am left with only myself, old and new parts, in striking clarity.