Every so often I meet somebody, usually another writer or aspiring writer who, when they hear my name, says, "Oh, I've read your books!"
I'm never quite sure how to respond to that, and here's why:
It's kinda like somebody saying, "Oh, you got your hair cut!" And leaving it at that.
Maybe folks think that by telling me they read one of my books they're saying "and I liked it." Otherwise, they wouldn't have bothered mentioning it at all. I'd like to believe this, but in my heart of hearts, I don't. I think it might just be the shock of recognition, the equivalent of "Hey, I know you!" And what do you say to that?
I suppose I could respond with "So, did you like it?" but frankly, this would take a stronger hide than mine, because what if they didn't? I've had somebody criticise my work to my face, and believe you me, it was NOT pleasant, so it's not something I'm likely to encourage. Also, if they've just blurted out the equivalent of "Hey, I know you!" they may not appreciate being put on the spot and asked to deliver a critique of my work. And then they might lie to get themselves off the spot, and I'd realize they were lying, and then we'd both feel bad.
That's why, if somebody declares, "Oh, I've read your books!" I usually just smile.