Shawn: It's Halloween!
Despite everything else going on, Shawn was actually excited to go costume shopping. All the acting stuff he did, that made him tired and stressed out and worried he'd let people down, but the part of it he actually liked was being able to pretend to be someone else, to act like they acted, even try to think how they think. Plus, everyone else got in on it too! "I can't wait to pick one out!"