Grammaretto
I was on a ship for 6 weeks coming to the UK from NZ. Admittedly it was no cruise but even with the daily routine of deck games, swimming, schoolwork (I was a child) meals, cinema and stopoffs in various ports, it was very boring when we were at sea for days on end.
"You join the navy, to see the world and what do you see, you see the sea".
Loved my cruise days at sea. No traffic, no pollution, no noise from shouty neighbours, no unwanted phone calls, no rubbish TV. Just peace, the far horizon, the odd ship passing a good book, and the odd G&T.
