I'm pretty much a cruise addict. Been on 78 cruises totaling 467 days at sea. I've been on Carnival, Celebrity, Cunard, Crystal, Disney, Holland America, MSC, NCL, Princess and Royal Caribbean. Basically, having a heroin addiction would be cheaper. And RJ can thank me that I don't post volumes of my cruise vacation pics each time I get back. LOL!
In all my cruises, there were only a few 'almost' horror stories.
On Royal Caribbean, we were stuck at sea an extra day when the port we were returning to was closed by a hurricane. Onboard, there was very little problem. They opened up all the phone lines so passengers could rebook air plans and had cruise representatives helping guests rebook any other travel plans (hotels, etc.).
On Carnival, my ex and I got what was probably Norovirus. It was lousy, but it's impossible to say if it was Noro because 1) we're not doctors and 2) our symptoms were pretty common to other airborne illnesses. Carnival put us on antibiotics and confined us to our cabin. Funniest part was when they sent free drink coupons to the room to help compensate us for the inconvenience (uhm, about those antibiotics ...).
On Disney, we had a sobering experience. During dinner my ex and I felt the thrusters engage. Since there's nearly no reason to go sideways in the open ocean, I excused myself and went up on deck to check it out. Once there, I saw a Zodiac boat floating aimlessly. It was empty with a large amount of bird feces on it. It made me wonder if the occupants tried to make it to the U.S. and didn't complete their voyage. BTW, in the Caribbean, this isn't an uncommon occurrence.
I had a friend who worked for Princess who confided in us that during one of their Alaska voyages, they ran into a whale with the point of their bulbous bow. Apparently, it didn't fall off for a week and had begun to smell pretty rancid. Sad for the whale and the passengers.
I guess that the insulated vacation bubble is occasionally popped by bad circumstances. But overall, real life on land is, too. I'd rather be at sea.