Damn, so many depressed people answering. Here's my take:
I'm single because I enjoy it. I was in a 4 year relationship from my early to mid-twenties and after a few issues we broke up with no resentment towards each other.
Ever since then I've only got more confidence, got in better shape than I was before, got better looking with age (don't look like a kid anymore, actually developed facial hair) and excelled my career.
I have fun dating regularly, but not looking for anything more than that. I genuinely prefer focusing on myself and my personal enjoyment and happiness, guess I've become selfish, but that's not a bad thing. The one thing I don't need right now is the commitment of a serious relationship, there's so much I want to do and I feel like a girlfriend would only hold me back.
But this is Reddit, so I'm probably a virgin, who knows.