I even spotted celebrity authors like Patrick Rothfuss (The Name of the Wind) and James Dashner (The Maze Runner) among the posters. I'm sure there were other well-known authors, but I'm horrible with names. Which might well be one of the things you should never say to a writer.
"That is such a flighty job. Why can't you be a physician's assistant, like your sister?"
"So, have you ever written, like, a real book?"
"I know you want to make big-time money, but do you actually have some sort of vision?"
"Do you write horror stories for a specific reason? What about your son? Do you write with his future in mind?"
"Oh, that's okay. I'll read your book when it's published."
"I always wanted to write a children's book - I just can't find the time."
Here are some more gems directly taken from Twitter:
And last but not least: