Has this ever happened to you?
You're out having fun (at a family party, a barbecue, a reunion, whatever), and somebody (an aunt, a cousin, an individual you put up with in college but didn't really like) will slide up and inquire:
Are you seeing anybody?
Do you think you'll ever get married?
And suddenly you're on the defensive, thinking of ways to convince this person that you're not defective, that you are actually a happy, successful, fully-functioning adult. (Shouldn't it be a crime in 2010 for people to demand from you why you're single and what you plan to do about it?)
The real problem here is that the question can often make the happiest, most successful, confident person feel somewhat...none of those things. But if it's asked of you, please know that many of your interrogators are unhappy in their own relationships. They may very well you resent you for the freedom being single gives you. So...
ALWAYS CONSIDER THE SOURCE.
In the case of people who truly care about you and "just want you to to be happy," smile and say, "Oh, I'm much too young to get married" when they start making inquiries.
SAY THIS EVEN IF YOU'RE SEVENTY.
I dislike the pressure people put on singles to "hook up" mainly because it can push those singles to date whatever comes along or -- worse -- put up with substandard behavior from a guy because they're "not getting younger" and they "need to stop being so picky."
(Definition of picky: Rejecting a loyal, loving, reliable, successful, fun man because he doesn't meet a height requirement. Or because he's bald. Or because you don't like his car. Face it, you gotta give a guy a chance.
Definitely not the definition of picky: Rejecting a guy who treats you poorly, demonstrates undesirable behavior, or is just wrong for you. Face it, you have to be attracted to a guy for a relationship to flourish.)
My advice to you is to love yourself. Take excellent care of yourself. Practice self-love, and you'll become irresistible to those who are capable of loving you and caring for you. You'll also drive people who want you to feel "less" because you don't have a man out of their tiny minds.