I went solo to Alaska in May and am going solo to the Med twice. I was really nervous about Alaska, but I set up the meet and mingle and met a lot of great people. Go to the activities that interest you and you will meet people with the same interests.
I wasn't alone on the cruise except when I wanted to be.
One guy I played cards with asked if I knew everyone on the ship because as we were walking one afternoon, 4 people said Hi to me.
Go and have a great time!!
Grand Princess May 2014
Sapphire Princess January 2014
Caribbean Princess March 2013
NCL Epic March 2013
NCL Jade October 2012
Crown Princess August 2012
Review for Sea Princess- Alaska 5/13-23 2012 http://boards.cruisecritic.com/showthread.php?t=1640072
NCL Pride of America Hawaii September 2007