Why are you single?" and
"You are already 31. Why are you still single?"
"You should be married now."

Okay. The last one is not a question but rude and ignorant.

Considering who is asking the question it can be very annoying especially in social settings. I'm Looking for smart and intelligent answers (just for the condescending people)

Some of my answers are:

I can't just get a guy from a store like I buy a tv.

Why I'm not married at my age? Does marriage have an age limit?

But I'm looking for deeper answers to silence those annoying people :-).

I'm a female.

Thanks a bunch!