> No, there are significant differences: [...] does not make them equivalent as currency.

Did I say rice was exactly equivalent to energy, or did I say that it was not too different? Surely you can see that rice is more analogous to energy than to drill bits.

>So while keeping some cash around against an emergency (or simply for market transactions – more on that later) might be a good idea, keeping nearly a year’s worth of expenses to make it through a bad harvest was not practical.

Hence the point of notes. "Rice is not such a bad thing to base your currency on" doesn't mean wallets should be literal fistfuls of rice grains in bags that you lug around.

I'm not a big fan of how abstract modern monetary systems are, and I'm still trying to decide whether they confuse people by accident or design.