Bruce Wayne was going to the theater one night with his parents, Thomas and Martha Wayne, when a man came out of the shadows and held his parents at gun point. He demanded Bruce's mother's pearl necklace. Right as Martha Wayne reached up to take off her necklace, she and Bruce's father collapsed. The man who came from the shadows looked in horror, not understanding what happened. Bruce looked up from the street in tears, while the man ran away. After the postmortem, it was confirmed that the cause of death was low calcium levels. From that day on Bruce Wayne lived as his alter ego Milk Man, to save civilians from low calcium levels.

Yes that is a milk mustache.