PALO ALTO, Calif. — He built his house on the water thinking he’d never leave.

It was five minutes from the Indianapolis Colts’ practice facility. It’s where his kids would grow up, where he and his wife would ease into middle age. It’s where he imagined storing a Super Bowl ring or two. Life was simpler then, “a binary existence” Andrew Luck once called it, when he still had so much in front of him.

“I was gonna play until I was 40 or 45,” he says.

For a moment, the thought lingers. A smile creases his face.

“You think you’re invincible. At least I did.”