Growing up, David Jacobson knew his father was a hero – he just didn’t know how much of one. His dad Russell served in Vietnam but rarely spoke about what happened, though David could see it was significant. His father, who had been a U.S. Navy corpsman, or combat medic, with the Marine Corps in 1967, walked with a severe limp – his right leg mostly useless – aided by a large brace and ever-present cane. Then there were the scars. Both legs were…