Cheese for the wife's lunchtime sandwiches tomorrow.
I did think about winging it:
"Special treat for lunch tomorrow dear: diet cheese sandwich."
"What's a 'diet cheese sandwich'?"
"Two slices of bread."
Then I realised I valued my testicles and put my coat back on.
I went to the supermarket a couple of hours ago and when I got home I realised I'd forgotten to get one item. I've just been back to the shop and got it.
True story.