What about if a disease occurs to you and you can't remember it? You'll lose the wallet!
Not a good idea!
My thoughts about that. What if you are loosing your mind the past view years? You get something on your head in an accident and lose parts of your memory?
What you are talking about is a rare cases which i think you were a pessimist but if you think it will never going to happen it will not. It's just a matter of believing but if it will do going to happen to someone, well they should have better to leave a clue to their trusted friends and family. It may happen to someone but like i said it will rarely to happen.