There are two things that I would really love to do, but they are so unlikely to ever be doable, that it really does not count as being on a bucket list, where you actually intend to do that thing.
The first one that I really wish I could do is to go one one of the cruis ships for just a short 3 day cruise down into the Caribbean and back. I would just love being on the boat, seeing the ocean and the sights along the way there and back.
The second thing is similar, and that is to take a cross-country trip on a train. I love riding on trains, and one of my favorite memories is when I went cross-country from north Idaho to Richmond, Virginia to visit my daughter when she was in the Army and station out there.
I went up in the vista dome car and could see everything in front and behind the train, and I spent most of my tome up there, just going back to my regular seat to sleep becasue it would recline so I could sleep better.