Sorry to hear you never found your rings.
Read all through this thread and it reminded me of the time my son left his wallet in the kitchen. It was his 13th birthday and he'd got a lot of money - from grandparents etc. - had about 150 quid in there. One of his friends had been in the house, and after he'd gone we couldn't find the wallet. The boy in question was a really nice kid but came from what you'd call a disadvantaged home (Dad was a bit of a drinker and couldn't hold down a job, and his mum who had been a nurse and the backbone of the family had tragically suffered a stroke at a young age and was more or less housebound as a result). I hated thinking it, but couldn't help but think he'd stolen it. There was no other logical explanation. One minute it was there ... next minute gone. I told my son that his friend must have taken it but he insisted "he wouldn't do that Mum, I know him, he just wouldn't do it' no matter how persuasively I rationalised that it had to be him, and so I left it there - son was upset over the money of course, but even though we never found the wallet and there was no other explanation as to where it was gone, he wouldn't hear a word against his friend.. Privately I always thought the kid had stolen it and was always a bit 'off' with him after that, and very wary whenever he came round.
Fast forward a couple of years and my fridge freezer packs up so I get a new one. You've guessed it. As we take the old one out - there, wedged down in the wire element bits that stick out the back was the wallet with all the cash still in. I must have put it up on top for safe keeping, and somehow it had slipped down the back between the fridge and the wall. I felt awful at the way I'd been towards my son's friend .... whereas my son was so certain 'I knew it wasn't him mum, he just would never have done it'. These two have been friends since their first day at primary school and at 18 are still best mates.