If you can't stand to talk about yourself, your needs, your desires, your discomforts, your insecurities, expectations, your disappointments, your motivations--if you don't like to explain yourself--then you'd best find someone with a very similar background to your own, because it maximizes the chances that you won't have to explain yourself.
The better you both are at talking things out--and you need to be really candid at how good you both are about this-the most you can handle the fact that if you do come from/reside in different social classes you will have different needs, different desires, different discomforts, different insecurities, different expectations, different disappointments, and different motivations.
There's quite a bit to be said for common or complementary intrests, of course, and I'd have a hard time dating a girl who didn't read, or obsessively watched television, or like to party and stone, but what her income/family status/station in life is doesn't really range high on my list of considerations.
But then, I may one day soon end up working at a bar (again), so to me, social class is kind of a fluid concept.
For example, one time I wanted him to come with me to visit some of my family in the mid west.