When you go into someone's house for the first time, do you notice if they have books and then what they are.

[NNadir]

I can't help myself from doing that. I form an impression based on what's on the shelves. Often I gather an impression that is correct; at other times, I'm mislead.

I once, when I was a kid, was very attracted to a woman with whom I'd spent a week as a house guest, but when I went to her house, her books were about being gay, so I kept my distance. Later a mutual friend told me that the woman was attracted to me, but thought I wasn't interested.

It turns out that the woman in question was heterosexual, but that her housemate was gay.