I used to always sail solo and absolutely LOVED it!!! Freedom to eat and drink where and when I want. I don't miss the single supplements but they weren't that bad. I used to frolic about in my room and balcony but, after the whole Erin Andrews debacle, I think that I would be a tad more conservative.
Meeting other solos at dinner is always a hoot. The vast majority of solo cruisers I have encountered are extreme extroverts. They love conversation and are rarely uncomfortable in any situation.