In all other cases except the Triwizard cup, portkeys only go one way at one specific time. Touching them again does not activate them to return to their place of origin. Also, when Harry grabs the cup a second time, it does not return him to the middle of the maze. It takes him to…
When a financial institution asks me my “mother’s maiden name” as a security question. Because it’s assumed that I have at least one and no more than one mother in my life AND that she married AND that she gave up her own name AND that that part of her identity was erased enough from my public history so as to be a password to access my private information.
Holy crap, I never realized.