The answer that my own personal crazy brain returned is this: the disciples were a bunch of practical jokers. Thomas had been taken in by them before and wasn’t going to fall for it this time. They had short-sheeted his bed, doused him with water, and sent him off to parties in totally unsuitable clothing. Makes me like some of the disciples better, actually. The funny parts of the Bible are definitely under-read in church and maybe even under-written in the documents themselves.
Anyway, I am not the only one who finds a comic connection in the story. During the announcements after the sermon, Bruce (the priest) mentioned that his son Jeremy wanted him to point out that the action unfolded in the story much the way it does in Sponge Bob, with a note that it is now One Week Later. Several years ago, Bruce drew parallels between Thomas the disciple and Thomas the Tank Engine, presumably because Jeremy was into the latter, although, you never know, Bruce could have a secret passion for wooden train sets and books with Obvious Moral Content.
Faith is a funny thing.