“I’m not happy with how he’s walking,” Samara said on Monday. She held Martin’s shoe upside down (his foot was absent) and ran her finger along the heel’s exterior tread. “See how it’s more worn here? He’s still landing too much on the outside of his foot when he steps. Shouldn’t his orthotics”—Martin wears custom shoe inserts—“correct that?”

I examined the shoe. I got excited.

“Samara, do you see this?” I asked.

“I do,” she replied. “He’s landing on the outside of his foot.”

“Forget that! Look at the whole shoe.” I pointed to the heel tip, the very end of the sole: “Deeply worn here, tread almost gone.” I pointed to the middle of the sole: “No wear here.” I pointed to the toe, where the tread curved upward: “Lightly worn here. Don’t you get it? That’s exactly the way a shoe gets worn when you walk heel-to-toe. Heel-to-toe, just like you’re supposed to. It got worn like this because Martin doesn’t toe-walk anymore.”

“Hey, that’s right,” Samara said. “He’s had these shoes for a while. It’s been months since any toe-walking.”

My mind jumped to the early days after Martin’s diagnosis, when he drifted on tiptoes despite our pleas for “big-boy walking.”

One more symptom of autism so far behind us that I don’t think about it anymore.

Samara seemed less impressed. “But what about Martin landing on the outside of his foot?” she asked.

“Oh, that.” I flipped over one of Adrian’s shoes and showed Samara the tread, deeply worn along the heel’s exterior. I shrugged. “Martin walks like a penguin, just like his father. There are worse traits to share.”