Except it’s your ID to get on and off the ship in each port (some countries require a separate gov issued ID but that’s for their customs- to reboard Disney just needs your KTTW), it’s the ID you use to prove you’re over 18 in the adult venues, and it’s the ID you use to claim you children including babies from the clubs.
If it’s valid ID to give you a baby I think it would be valid to give you a drink.
GAME. SET. MATCH!