You know what's interesting though,  I bet somewhere around 50% of the coins ever mined,  especially in the 10,000 coins for a pizza day,  were deleted, formatted,  never backed up,  experimented with.  Etc Etc..

I bet we won't ever have have 21 million coins...     or as now the Total Number of Bitcoins = 11,097,600   

I bet people actually control closer to 5 million or so coins.  The other 6 million were formatted, wiped ,  lost, etc.