When he was 4 years old, Ryan started talking about going home to Hollywood. He often directed imaginary movies, yelling “action!” His parents didn’t think much of it until his nightmares started. “He would wake up grabbing his chest and saying he couldn’t breathe. He said that when he was in Hollywood his heart had exploded,” wrote Jim Tucker, M.D., a leading researcher of reincarnation cases, in his book “Return to Life: Extraordinary Cases of Children Who Remember Past Lives.” Dr. Tucker is also an associate professor of psychiatry and neurobe...