I travelled solo last year on a 4 day cruise to Canada with Carnival. I asked for a large table at dinner and I was seated with ladies who travelled alone also. It was a nice mix of people sane, strange, & a little nutty. Conversation was good to debating who was going to be President. couple of the ladies went ashore together. I went to trivia & shows. I sometimes met up with one of ladies from dinner. I enjoyed the cruise. It was short & sweet.
I also went solo last year on NCL for 7 days. I found myself getting a little lonely for a travel partner the last days. The people were not as friendly on NCL. I still did the same trivia, shows, & relaxing. NCL had two parties for pass cruisers which was very nice. People were friendly there. Since NCL does not have assigned seating I think that made a difference in meeting people.
I will be travelling alone again on 5/16 on Carnival. Eight days this time! I have asked for a large table again for dinner. So I will see what happens. One thing I know I will still enjoy my cruise.....No other way to vacation.