Literally

I am a very literal person. To a fault. I say exactly what I mean and I can't understand symbolism or sarcasm. I've always struggled with this sort of thing. You know that old saying, something about, people who live in glass houses shouldn't throw stones? The person administering my personality test a few years ago asked me to explain what that means. I said, and I quote,

"Well, they'd break the windows."

I remember this very clearly, because she just stared at me for a few moments, like I had absolutely lost my mind. I got really embarrassed, and realized that apparently I had not said what she was expecting, and finally she said, "I've never heard that one before."

I STILL don't know the correct answer to that question. What does it mean? I think its pretty reckless to be throwing stones in a glass house, you're just asking for trouble. That seems pretty obvious to me.