It was at BookExpo America, a booksellers convention that I went to three years in a row when it was in Chicago (I worked part-time at Waldenbooks, which was my “professional” credentials to get in). I had to pay the $100+ weekend fee, but the free books and other paraphernalia, many of which were signed by the authors, made it totally worth it! The first year, I came home with over 200 books, most of which I gave away to coworkers at both jobs. I got smarter with snagging free booty and didn’t overdo it in subsequent years.
Ms. Andrews was signing one of her children’s books. She was in the upmost tier of authors who were not only signing in the signing area, but you had to get a ticket for her signing to get a spot in line. I had learned my first year to show up for the ticket dispersal line by 5:30 am, since they started handing them out at 7. As I was walking away from the ticket booth with tickets in hand, they announced that her tickets were all gone, and you could hear the groans of disappointment echoing around the room.
She was everything I wanted in a celeb encounter—very nice, showed interest in me in a few words, listened patiently while I babbled how much of a fan I was/am, then politely waved me off while the next person in line stepped up. I will never forget it!
Edited to add a movie-related BEA story. In 2001, the Houghton-Mifflin booth was all Lord of the Rings movie tie-ins, including a tv showing the internet-exclusive trailer. My dial-in modem at home sucked so I hadn’t seen the trailer yet, and the official trailer was still months away, so I had no idea of what the trilogy was going to look like until I saw it at the booth. A bunch of us were transfixed and marveled that it looked like they might actually pull this off!