I have not sold one to miss, but I did lose one. It was about 15-20 years ago now. A blue SAK, possibly a huntsman, I remember the saw blade. My sister gave to me after visiting Switzerland, customised with my initials on it (SM). Then I went ahead and lost it while fishing.
I felt bad.
She passed from a brain tumour last year, it would be awesome to somehow rediscover it, but I suspect it will never be seen again.