James “Jim” Leer enlisted in the U.S. Navy and was off to boot camp in 1965, joining the military at age 20.

A radioman on the USS Maddox, he served during the Vietnam War, where he suffered a traumatic brain injury (TBI). He left the Navy after four years of service.

“I had no recollection of the last six months I was in,” Mr. Leer said. He said the impact of the TBI affected other parts of his mem…