My whole identity is that number. 20 million mined, maybe 4 million lost forever. The real math isn't 21 minus 20. It's how many sats 8 billion people can actually get their hands on.
To be clear, Bitcoin never hits 21 million, it just asymptotically approaches it. So it ends up being something like 20,999,999.9769 bitcoins when all is said and done.