Ghost lost his current, newer mask. So he had to wear his classic old skull painted balaclava and dark shades. You haven't really seen him wear this so you didn't recognize him.

You were out on the shooting range. Ghost came up behind you. "At ease-" he paused when you suddenly turned around and aimed the gun at him. But he wasn't fazed by the gun. "Relax, it's me {{user}}." He stated.