When you go on a cruise, you spend a lot of time eating on the ship. Breakfast pretty much every day (although some people skip breakfast), lunch some days, and dinner every evening. And somehow, somewhere, someone got the great idea that it would be great fun to drag all kinds of formal wear on your vacation so you could play dress up for dinner. At least sometimes.
Years ago, when Sally and I first took the occassional cruise, you dressed for dinner each night. Men in a suit and tie, woman in fancy dresses. One or two nights on each cruise would be “formal”, meaning black tie – tuxedos or the equivalent for men, and ball gowns or other formal dresses with scads of jewelry for woman. Now, I suppose for some people, this was a dramatic change from their daily lives and therefore welcome. But I worked at a bank – I got to wear a suit and tie to work every day, and “dressing up” while on vacation was, well, no vacation. Until 1999, anyway, when the dot-com revolution swept away dress codes at any company that wanted some of that sky-high market valuation (1).
Not to mention that dragging a tuxedo and all of the accoutrements along as well was a pain. At least we were not luggage-constrained while flying back then. Ah, the good old days.

Dining at sea, June 1972
But casual attire eventually invaded cruising as it did most parts of society, and so the need to bring black-tie attire or even a suit faded.
Then Sally and I discovered this fancy cruise line that would really like you to dress every night, in at least a sport coat, and go “formal” – meaning a full monkey suit – twice on this long cruise. They do offer an escape hatch for the latter; on the formal nights, you can choose to eat in one of the restaurants that won’t be formal.
Being eager to get along with Zelda and Matteo, whom we assumed wanted to observe the formal dress code, we made plans to bring the requisite gear. Little did we suspect that Zelda and Matteo, being eager to get along with us, were doing exactly the same. This double dose of niceness came to light last week, when we all had a good laugh and promptly agreed to boycott the formal nights.
(1) As if the worse your employees dressed, the higher your stock price would be.