In nearly 35 years, I have not lost a watch, nor a wallet. I have nearly lost a finger a few times (don't turn on a drill while you are messing with the chuck).

I have also lost a lot of skin from different parts of my body.

For a chip to stay, would need to be somewhere inconvenient and deep. Certainly nowhere convenient that a reader could reach, unless its RFID style in which case I have other concerns...

At least until the Yakuza find out about it.