I've never been on a quilt retreat, but I used to go to a lot of conferences for work. One year I sat next to someone who was quite distracted. As we talked during the breaks and over lunches, I learned that he and his wife were in the process of adopting an Eastern European baby and were waiting to hear when they could pick her up. We became good friends and stayed in touch via email and other work events. They now have 3 children from the same orphanage (2 are siblings).
I share this because, like most things in life, sometimes you get lucky and make a new friend. Other times you grit your teeth and make the most of it.
BTW I would never get anything done at a quilt retreat because I'm am easily distracted. I'd have to sew string quilt blocks or some other "mindless" type of project otherwise I'd be constantly messing it up!