For the most part, I’ve mostly played string instruments – those with frets, especially. Once, in an art class, I made a mandolin out of tin can. I had to build the neck myself, made the frets out of nails that I cut and the then hammered into the wood.
Frets are so much a part of my sense of how things are organized, I may have missed the double meaning of this entirely. I thought only of someone running fingers over frets – I didn’t even consider that fretting someone might also be to upset them – to cause them to fret, as it were.
My mandolin made from the olive oil can was called a Candolin. I still have it. It’s hanging in my mother’s music room. It’s hard to pack and move. There is no case for the Candolin.
Also – it doesn’t play like a mandolin. The tuning is such that it is unpredictable. The frets aren’t placed precisely enough for predictability. So the Candolin is not particularly useful or tuneful instrument. I cannot really play much upon it. Pretty much only clown songs.