WASHINGTON — Three times, mainly by chance and in very different circumstances, Sgt. First Class Cory Remsburg has met President Obama.

They were introduced near Omaha Beach in France in 2009, when Sergeant Remsburg was part of a select Army Ranger group chosen to re-enact a parachute drop for celebrations of the 65th anniversary of the D-Day landings in World War II. The second meeting came less than a year later at a military hospital outside Washington, where Mr. Obama was stunned to see among the wounded troops from Afghanistan a familiar young man — now brain-damaged, a track of fresh stitches across his skull, and partly paralyzed.

The third time was two weeks ago in a private visit in Phoenix, where Sergeant Remsburg did something that neither Mr. Obama nor military doctors would once have predicted: he stood up and saluted his commander in chief.

There was more. Grasping his walker, “Cory took a step, then another, and then another,” Mr. Obama said later, “all the way across the room.”