ok!
Im a nanny... i have the biggest bunch of keys EVER. House keys for my house, my mums, my dads, my grandparents, current place of work and the previouse 3 jobs, (where i go occasionaly and are all happy for me to keep their keys) as well as my car. + 2 key fobs to get me into local sailing clubs
(24 keys in total)
I Have never lost my massive bunch of keys. (It weighs a ton, and makes a massive noise if dropped)
However one day one of the keys (of my old job) came off the key ring. (they had given me a flimsy key rings with 3 keys on to attatch to my key ring and because it was a flimsy key ring it just came off)
The thing was they had just had massive building works done on their house, and had all of the doors with the same yale key. 6 doors in total, 5 of those external doors.
The key went missing on the school run, ie between their front door and my car (massive driveway) or actually at the school.
Asked in the office at school and looked all over the massive drive way but we never found it.
Due to the possibility of the fact that the key might have been on the drive they had to change all 6 brand new locks. (less than a month old)
Whilst i was mortified they didnt expect or even ask me to pay.
(Even if they had i wouldnt have paid.... I had not been 'negligent' and had attached the bunch of keys to my key ring with the key ring they provided for me)
So far that is the only key i have ever lost!