gnu

The anchor spins freely in the hole, which I think is expected.

Sounds like your hole is too big, you normally want to start with the plug being an interference fit. Try tapping it in with something to take up the extra space around it.

You just remember where you put the thing, the concept of where it is still remains even if you can’t visualise it. Similarly I can still remember routes and recognise people even though I can’t really visualise either.