I think a closer analogy would be forgetting basic arithmetic as a concept. Imagine how hard it would be to work with more complex math without understanding what division is. How do you prompt the genie, or understand its outputs, without the foundational knowledge?
Is basic arithmetic something that can be forgotten? Studies have suggested that even infants have an understanding of basic arithmetic. There is a reasonable likelihood that it is something innate.
As we're only imagining anyway, let's ignore the genie for a moment. If we did lose our sense of basic arithmetic all of a sudden what would life at its core even be like? If there were two apples on a table you wouldn't be able to comprehend what happens if you took one. Would we even be able to function like that?