The instant they bowed, he remembered. Targum Pseudo-Jonathan on Genesis 42:9 reports it without fanfare: "Joseph remembered the dreams he had dreamed of them."
The sheaves and the stars
Twenty-two years earlier, Joseph had told his brothers two dreams (Genesis 37:7-9). In the first, eleven sheaves bowed to his sheaf in the field. In the second, the sun, moon, and eleven stars bowed to him. The brothers had hated him for the dreams, and those dreams were a major reason they sold him. Now the first dream is coming true before his eyes. Ten sheaves — ten brothers — bowing face to the ground in his court.
Why the dream remembered matters
The Aramaic paraphrase, whose final redaction belongs to the Land of Israel around the seventh or eighth century CE, adds nothing supernatural to this moment. Joseph simply remembers. But the memory changes what happens next. If the first dream has come true, the second is still outstanding — the second dream had eleven sheaves, eleven stars, and a moon. Where is the eleventh brother, Benjamin? Where is their father Jacob? The harsh test Joseph is about to stage — accusing them of spying and demanding Benjamin — is not random cruelty. It is Joseph trying to complete the dream that is still unfinished.
You are spies
The accusation — to have come to see "the nakedness of the shame of the land" — is an Egyptian political charge. Foreigners arriving separately through different gates looked like agents mapping defenses. Joseph uses the charge as leverage.
The takeaway
A dream delayed is not a dream denied. Joseph lived twenty-two years between the dream and its fulfillment, and in the meantime he became the very ruler his sheaf foreshadowed.