It is my understanding that they invented Bitcoin as a token to use in peer to peer transactions, so people could use it instead of fiat which was controlled by and manipulated by governments.
This was of course in response to the Financial Crash of 2008, and from a passion for math , software development and a passion for cryptography.
Cryptography
Ironically cryptography was invented to help the Government hide things, as in secret communications.
But in modern cryptocurrency this mathmatical tool is used to create transparency, as in the transparent blockchain ledger, also called a blockchain explorer. WHich is of course the opposite of secrecy.
Bitcoin Pizza Day
So this famous event where Bitcoin was atually used to purchase something is very important, as it showed by example that you could use Bitcoin to buy something.
We sometimes focus on the fact the someone paid a bunch of Bitcoin for a pizza.
But that causes us to lose site of what this really means. It meant you could use Bitcoin as a means of exchange and commerce.
This pizza purchase was the precursor to the use of Bitcoin to purchase almost anything on the Silkroad.
Silkroad
This was the first? and biggest Bitcoin Peer to Peer market, where you could buy many different things with Bitcoin.
While it is famously or perhaps more precisely infamously known as a place where people used Bitcoin to buy drugs, it was a general goods and services market.
Unfortunately the extent of criminial activity led to the creator of the exchange being arrested, and imprisoned by the US Government.
Fiat Money
While many condemn cryptocurrency as a tool used for criminals, it is important to remember two things: First cash fiat is practitically untraceable, and it the true medium of exchange for criminals and most of the crime in the world for the obvious reasons it is untraceable and extremely fungible. Second, is that Bitcoin is very traceable as people must use bank accounts to on ramp cash to Bitcoin and offramp their Bitcoin to cash when they make a profit from their crimes. SO not only can the government trace all Bitcoin transactions on the Bitcoin Explorer or ledger, but they can also trace the movement of Bitcoin to Centralized Exchanges and to the Bank Accounts connected to the people utilizing Bitcoin.
So Pizza Day is not a meme to make fun of someone
The guy who gets parodied and memed on that day is not meant to be the butt of jokes, although he is...
He is instead being immortalized for making the first Bitcoin transaction, and proving to the world that BItcoin could be used to buy something. Once he did this, it started a wave of activity which has led to where we are now.