You have 10 people on an island and each needs 5 fed shells in their pocket to transact business.
But the good news is that you can always find more shells, though there may be a limited supply. But when you convert them to paper, and you increase the population by ten, and increase the “paper” shells by 500, well you end up with inflation. And when you increse the paper shells by 10,000, you end up with hyperinflation.
Shells are from the titania musclock and not possible to cut in half without diamond tipped saws, that have not been invented yet.