Contributing to a Conversation

On Tuesday evening while my mother and I were waiting to do the touch-screen voting, one of the clerks, the man in front of my mother, and my mother started having conversations about jobs, etc.; then, the clerk brought up that she likes to play Solitaire and other online games. Therefore, the man said that he likes to play Spades, then my mother said that she likes to play Solitaire and Free Cell. Then, I said that I like to play Demon Solitaire; however after I said that, the clerk and the man looked at me with their mouths open till my mother asked, "Demon Solitaire?" and I said yes.
Gees, why were the clerk and the man looking at me with their mouths open? Because I really don't think that its scary when someone says something to contribute to a conversation. Furthermore, just because I say something to contribute to a conversation doesn't mean I'm a dangerous person.