Let's say only 300000 people own bitcoins today and they all decide to hoard their coins for 20 years. How will this new money spread to the rest of the population?
Let's say dollar bills turned into butterflies and flew away and all the Chinese decided to jump into the air at exactly the same moment...
Hah. How about we go for a realistic example. Say there was a small group of people who whenever they spent some of their dollars, there was an organization that would print up some more and give it to them. And it wasn't even illegal. Suppose now that there was another currency where when you spent it, it was gone no matter who you are or who you know.