Being single and happy with it requires confidence in yourself and your ability to keep a job, pay your own bills, entertain yourself, interact with family and friends as well as find satisfaction with your accomplishments and lifestyle. Over time, it becomes easier to reach those goals without seeking the approval or help of another person without the heartbreaks that are so pervasive in today's world.
The benefits of being in a relationship include having someone around to keep you company, share events of your day, give support when times are tough, and fulfill the need for a human touch, whether that be a hug or sex. When you start feeling sorry that you're not in a relationship, you remember a partner who's hard to please, never satisfied with all you do, snooped in your e-mail, followed you around like a puppy, and subtly tried to control you whether you the male or the female. It would take quite an effort to find someone willing to put up with all your quirks and who could measure up to all the things you would require from a relationship.
After some time of being alone, you ask yourself if you're willing to change aspects of your life to accommodate another person. A relationship requires accountability to another person, a willingness to compromise, share the closet and the bathroom etc. It means letting the other person know your schedule, finance, going to bed early enough that you don't interfere with the other person's ability to sleep and get up for work.
You like being able to get up in the morning, sitting in the quiet drinking coffee and checking your e-mail, fixing breakfast if and when you get around to it. You like making your own decisions, without consulting another person about how much money you can spend or what television show to watch. You like filling the closet full of clothes without having to share your limited space. You like eating the foods you like without worrying about someone else's preferences. You like visiting your family whenever you want, or being a hermit when you feel like it. Being single definitely has its benefits, yeah?