This is interesting: it's the sort of quip that, if said extemporaneously in conversation, would probably get someone to laugh. The funny thing would specifically be referencing back to a conversation/event that happened a few days ago. The thing that makes it less funny in the compressed form is that you don't have to put the 2 and 2 together of "oh yeah, that's an event that happened a few days ago which is related to this situation" because the compressed joke has spoon-fed you the context.
Maybe jokes were such a novel form at the time that even the compressed form was still funny back then?