I have sailed alone once in 2005 and again in about 7 days!!!!
I'm a pretty independent person, but I also am always concious that I am alone and that I should take precautions for that reason.
I made sure to book Carnival excursions as I knew then there would be lots of other people around. I didn't get in a taxi alone and ask them to take me somewhere (ie into town shopping). I guess just using common sense. So many people forget it at home lol
I had a blast on my last Carnival cruise. It was a 7 day West Carribean from Miami on the Triumph. This one will be a 8 day Exotic out of Fl Lauderdale on the Miracle.
The biggest downfall for me is not having the extra luggage limit on the airplane 
P)
For dinner I was sitting with a group of about 7 other single people. Some were in groups of 2 (ie two ladies) but we were all divorced, single, etc. At the pool I was never far from a conversation if I wanted one. The shows I didn't feel awkward being alone. In fact, I never felt awkward being by myself. Some of my dinner mates were women of my age group so we often went to the piano bar together after dinner.....or we would meet up for other things (casino etc). I had an ocean view room and they got upgraded to a balcony so we had a party in their room one night and I got to tour the balcony cabins.
As I said earlier, a little common sense goes a long way. You will have a great time I'm sure of it!!!!
