Aaron Hern's friends back home in Martinez, Calif., know him as a perpetual motion machine. His mother wonders if they will recognize a slowed-down version.
"I think his friends will be shocked because he's not the Aaron everyone knows, running and bouncing off the walls," says Katherine Hern.
He was so energetic as a toddler that Katherine and Alan Hern directed their son toward sports at an early age. They think his fitness has helped him in his recovery.
"He's got a good, strong body, and the doctors thought his legs would be worse," says Katherine, who was running her first Boston Marathon this year. They're bad enough: "Pretty torn up, from hips to ankles," she adds.
Luckily, the 11-year-old didn't break any bones or damage any arteries. He was released last Wednesday from Boston Children's Hospital.
In the chaos after the bombings, Aaron's parents didn't know where the ambulance had taken him. Finally, they found him: He had been checked in as Patient B in the emergency room at Children's.
The first question Aaron asked his mother was whether she finished the Marathon. (She did.)
"He was all hooked up, and he could hardly talk, but he was worried about me, bless his heart."
Aaron was excited to have visits from Michelle Obama, Governor Deval Patrick, former governor Michael Dukakis, and, most of all, players from the Oakland A's, the Red Sox, and the Bruins. "It was amazing, and a huge part of his recovery," says his mother.
She knows her son is better because his goofiness is back: He's been doing the comedy riffs in the funny voice he loves. "He makes me laugh," she says, "and that's something we all need right now."
On Wednesday, Aaron turns 12. "It will be the biggest and happiest birthday," Katherine says. "Just the fact that he has another one."
Bella English can be reached at firstname.lastname@example.org