Why did Ishmael stop dating Zainab?

From the text:

I dated her for three weeks, but then she began to ask too many questions. Where was I from? What was it like growing up upline? Upline is a Krio word mostly used in Freetown to refer to the backwardness of the inner country, its inhabitants, and their mannerisms. I was unwilling to tell her anything, so she broke it off. That was the story of my relationship with girls in Freetown. They wanted to know about me, and I wasn’t ready to tell them. It was okay. I liked being alone.