But I couldn't remember the context from which a synapse of mine had stored "jam today," so I had to search. Wikipedia gave the source - Through The Looking Glass:
"I'm sure I'll take you with pleasure!" the Queen said. "Two pence a week, and jam every other day."That was the remembering part. Then came the learning -
Alice couldn't help laughing, as she said, "I don't want you to hire ME - and I don't care for jam."
"It's very good jam," said the Queen.
"Well, I don't want any TO-DAY, at any rate."
"You couldn't have it if you DID want it," the Queen said. "The rule is, jam to-morrow and jam yesterday - but never jam to-day."
"It MUST come sometimes to "jam to-day,"" Alice objected.
"No, it can't," said the Queen. "It's jam every OTHER day: to-day isn't any OTHER day, you know."
"I don't understand you," said Alice. "It's dreadfully confusing!"
The Queen's rule is a pun on a mnemonic for remembering the distinction between the Latin words "nunc" and "iam" (sometimes written "jam"). Both mean "now", but "nunc" is only used in the present tense, while "iam" is used in the past and future tenses, much like one use of the English word 'then'. (It is not clear if Carroll invented this mnemonic or was merely quoting it.)I had I think three years of mandatory Latin in high school and won a prize once, but had never heard this mnemonic. There's a lot of content in Carroll's writing that we never appreciate when we read the works merely as children's tales.
You learn something every day.