I love going to retreats...for all the things that have already been mentioned.. The place that we go to is a beautiful place with walking trails, a lake and at the foot of a mountain. Just being out in nature where you can rise and just praise God for all the beauty is worth the trip. I live 20 minutes away but I always pay to stay there with my friends.
The retreat organizer has games and a class is offered for those that want to take it otherwise we take our own stuff. I usually take a couple of UFO's stuff for a new pattern or I end up taking the class. We have a local store bring their "store"and they have anything you might need or forgot to bring.
If you forgot something that the store does not have most quilters will lend you one thing or another.