I'm not single now - but I was for 20 years between marriages. I hated waking up alone. I hated evenings and weekends alone. After 20 years of prolonged periods with no dating whatsoever it became difficult and I seemed to be the only one alone. Sex alone isn't much fun either :-) I hated being single when I had repairs to do in the house which needed two people. I didn't link being single when I travelled. It isn't very romantic to watch a sunset by yourself.
When I think about it there wasn't much I liked about being single. I did develop lots of hobbies and interests and I travelled and kept really busy but these activites just filled the space I wanted for a relationship.