"I usually don't mind, and would regularly offer a flippant, uncaring response. I'd cite things like time or money more often than not, as having a girlfriend would require both and they are resources I have no interest in squandering on anyone but myself at the moment. Frankly, I barely make enough to do that as is. See, a girlfriend is really a luxury I can't afford. And yes, that's essentially what having a girlfriend is, when you boil it down to the most basic terms: a luxury.
The honest truth is that I'm quite fine in being single, and have no interest in undertaking a course of action that would make me otherwise. My mind is a mess and my life is far from ideal, and adding a girlfriend into the mix will only further complicate matters. Besides, I'm happy as things are now, with me having time for my projects and interests, as opposed to having to keep my thoughts occupied by thinking of someone else."
-So I'm Single, Harvey's VIII of Swords