I really don't get it why the first 17 million was mined within 9 years and the remaining 4 million is being predicted to be mined probably more than 9 years.
Bitcoin was developed to simulate scarcity, like for instance Gold. The difference is, we know exactly how many bitcoins there
will be and when the Block reward will stop. In Gold, new deposits are frequently found, so they are dealing with unknown
parameters to determine it's value. After the Block reward runs out, these miners will compete for the miners fees and we
hope that would be enough to sustain their profits.