I just experienced a sudden stabbing pain in my right foot. I was doing stuff in the garden (summer's gone though), and there it was. It felt like a sharp stone that had wedged itself between my shoe and my foot. I was totally dishearted. ****, it's back!
Looked at the foot: nothing to see. Looked at the inside of my shoe: nothing to see.
Put shoe back on, stand up. Screech!
Damn PN!!! ... I felt a wave of nausea coming up.
5 minutes later, when I took out my glasses, I noticed... a (black) screw that had found itself screwed into my (black) shoe, with the (sharp) point just underneath the surface of the shoe.
I can't say how relieved I am to have found that screw....
Sure, I had had occasions this summer when I felt ants (there were none) and felt ants ("hah, not gonna bother looking!" - when there were in fact ... ants all over my ankles & foot

), but this one had me seriously scared.
Not sure there's a lesson here, just wanted to share.