I use notebooks to write down my favorite photo numbers etc (see last photo) and I was using an old notebook (I've had many notebooks through the decades). I stumbled across these pages that had numbers which are from the mid-80s. What are they you ask? This is how we used to have to keep track of prices/money before computers.

Here was the P&L for the month. The Futures and Exchange Commission regulators probably would frown on this type of bookkeeping today.