Max walks up stairs by himself for the first time: the video

For a couple of years now, Max's physical therapists at school have been working on getting him to independently walk up and down stairs. This is tricky for him, because it involves grasping a railing (Max's hands don't always like to open up fully), core strength and coordination.

Using stairs is one of those things I never once in my life thought about until I had Max. After he started walking at age 3, I realized just how many movements are required to get you up and down stairs. Max has given me all sorts of new perspective on (and appreciation of) the ways bodies work.

I've always held Max's hand and supported his back as he walks up stairs in our home. Going down is harder for him and more perilous, and makes my heart lurch every time.

And then. We were on vacation at Smuggler's Notch, and Max decided to go up the stairs alone to our condo.

I was giddy. Jump and down and squeal "YEAH, MAX!" giddy.

What I also loved: How proud Max was of every single, hard-earned step.

When milestones like this happen, I flash back to my first meeting with Sue, the most lovely Early Intervention coordinator. Max was a month old. He lay on a blanket on the living room floor as I told her what had happened to him, and my fears about his future. Sue stared at me kindly. "He will surprise and amaze you, you'll see," she said.

He's never stopped.