This is a silly but true story: last year, my friend queued for 20 minutes, got to the till, and realised her wallet was on the kitchen counter. She had to beg the nice lady behind her to pay for her Brussels sprouts with contactless. Check your pockets before you leave the house. Keep your phone charged for the Morrisons app, too.
It sounds basic, but panic-brain is real. I once bought a tin of beans three times in one trip because I couldn’t remember if I’d already grabbed one. We all lose our minds a little on Christmas Eve. It’s part of the tradition.