"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!"
Or, to put it biblically, "expectation delayed is making the heart sick"