There is nothing about creating addresses that is like "registering" on the blockchain nor are they "assigned" by the blockchain. You generate addresses by generating a random number (the private key) and then manipulating that with hashes to get to the address. This is done offline. Technically every single address ever already exist, people just need to guess the private key for the address.
Ok, thanks, that is helpful. However. To take your explanation one step further - Does that mean I could theoretically "see" a public address already existing on, say... blockchain.info, before it was technically ever generated offline?
That's the part I don't get. How is the address visible on these sites if the address was created offline? I can't see how they could already be there, that would a lot of data right? Thanks again and sorry for still trying to understand!