The price of Bitcoin in Jan 2011 was 33 cents.
So for USD 800, we would have been able to buy 2424.24 bitcoins. Let's round it off to 2425.
Today's Bitcoin price as per coinmarketcap is 7717 USD.
So those 2425 bitcoins purchased in 2011 would be worth 2425 x 7717 = 18,713,725 USD.
That's 18.7 million USD
That means you would have been chilling on the beaches of the world today.
You should be sitting pretty right now if you still have these BTC in your possession.