[intelliot]

Nobody knows how many dollars are still in circulation. They have good guesses, but nobody knows about the millions in cash that was lost/burned/buried in the desert. It doesn't matter. Supply and demand doesn't rely on the total number of bitcoins in existence; only the number that are available on exchanges. And with blockchain analysis, we can have a very clear picture of bitcoin circulation - much better than with traditional currencies.

[toyg]

With fiat money, this is not a problem, because that's only one of the available parameters to determine the relative value of a currency. Also, inflation constantly pushes fiat currency value towards zero, so your stashed 1970 dollars are now worth much less. Bitcoin, being deflationary in nature and not linked to anything, is a different ballgame.