It least twice so far, I've had dreams about expired film.
It always starts out where I'm finding myself in an unfamiliar camera store. I tend to take a look at the used equipment bins and the expired film bins whenever I'm in a camera store, just to see what's there.
And then I'll discover that there's all sorts of interesting old expired film. Invariably it's a previous generation of film or an interesting discontinued film, and it's really old, so it's guaranteed that it's going to do something interesting when used.
And then I leave with my purchase, wake up, get excited about shooting my newfound expired film, and then realize that it was all just a dream.
At least it's better than the dream I get that I'm getting paged for work where I wake up and realize that the sound of my phone's message beep and me checking the message list was all a dream.