Welcome home, Pamela! I'm really happy to hear that you enjoyed your first sailing with Disney Cruise Line! The Dream is such a magnificent ship, and of course Castaway Cay is my favorite beach in the world!
I'm sorry you forgot to pick up any souvenirs at Castaway Cay, but I completely understand how you can lose track of time as you enjoy all of the activities on the island! Currently, guests cannot purchase Disney Cruise Line or Castaway Cay merchandise after the cruise. However, the
Disney Store website often sells a small selection of Disney Cruise Line and Castaway Cay items. Some of these might be the same ones you saw on the ship and the island, but unfortunately the selection is not nearly as great as it is on the island and onboard the Dream.
Take a look at what they have to offer and see if you spot a must-have souvenir! Merchandise varies and changes frequently, so if you don't see it now, stop back again next month and you might find that additional cruise items are added. Of course, you could always book another Disney cruise and purchase everything you'd like at Castaway Cay! I'm sure you'd like to go back!
I hope that helps, Pamela!