I normally behave the same. I don't ask people about their lives. They speak about it if they want to. And neither I judge them.
But the image you have of someone is built on what they tell you. If the person lies you, then you appreciate a dream, a fiction.

Moreover if the person wishes to tell you more about her then why should she lie? If she speaks about very personal feelings, it is because she is confident in the other person. Then she should tell the truth, right?
Maybe some persons enjoy playing roles, just to know how far they can get, and this is very scary.