The analogy doesn't stretch further than being a cute graphic. Individual bitcoins don't exist in any meaningful way, nor do the individual specks of bit-dust. There is no notion of 21 million coins, numbered 1 to 21,000,000.
Sure there is-- block 0 contains coins 0-49, block 1 coins 50-99, etc.
If you get sent 500 bitcoins, they can all be traced back to generation transactions, so you "own" a bunch of little pieces of land in bitcoin-world.