Like you, Bags, I attach little importance to things. My sister had put her passport (somewhere safe) and when I went over to bring her back to France for a holiday, we turned her house upside down, and eventually it turned up in a old suitcase which she swore she hadn't opened in years. Hm.....she loses things all the time or has them stolen.
I find the best thing to do with important documents is to file them at once in a folder, clearly marked, in case of my death, and put it in a plastic crate. I don't have any jewellery now, having given it all to my daughters, except one ring which I wear all the time.
I did once leave my credit card in a cash machine in Egypt but somebody took it into the bank for me so I was able to get it back on production of my passport.
I think if anybody broke into my flat to steal, they might end up leaving me something instead. I have moved seven times in the last ten years, mainly to furnished rental properties in France, so my possessions have dwindled.