Ugh some people just don't get it

I was in such a good mood when I got to the park when this India(n) man comes up to me. He starts asking me all these questions...
Him: What are you doing.
Me: Getting some fun exercise
Him: Are your children all grown up (now how did he know I had children?_
Me: Yes
Him: Well are they in college?
Me: No, one already graduated and one is married and expecting a child.

By now this is really getting on my nerves.
So then he says Is your husband at work?
So I say yes.(I'm divorced but I sure wasn't going to tell this guy anything else).
And he says, "And you are just here doing this?"
So I say, "He's at his job, and I'm at mine.I have to practice during the week so I can do shows on the weekend."
Well, that totally confuses him. And things just kind of went downhill from there.
Finally I just turned my back on him and he left. But that was the end of my good mood. What the hell is wrong with people? And more to the point, why can't I just say, "Sorry, I don't give strangers personal information." That would have been rude but would have nipped it in the bud.

Now I'm using the library computer. I should have practiced longer, but I'm not in the mood now.