I know there are a large number of them. I am one of the sad souls who did not take it seriously and lost my whole wallet after I invested $1,800 into 100 of them a long time a go. It happens and good luck to whom ever finds them.
I am sure it will never be found, one weakness or maybe power of the bitcoin is if missing will really not be found again. Maybe this is what we must think together so that stocks remain stable.