Everyone has had it.
Where you get a pebble or something small in your sock that irritates your foot with every step.
That was this morning.
I spent about 4 minutes taking on and off my sock trying to locate whatever it was that irritating my heel.
I didn’t locate it, but after taking the sock on and off three times it was gone.
I had to turn the sock inside out and sweep the whole of it with my hand before it felt fine when I wore it.
Robots did not help.