A user of Bitcoin gave us a story of how he lost hundreds of thousands of dollars of BTC during a wallet transfer.
The Bitcoin user tried to transfer a wallet to a new computer without having the authentic encryption password linked to his private key storage.

How it happened

The Bitcoin user known as "Onnar" who gave the testimony which was published on Reddit, claimed that he lost access to 2.6 BTC from the false transfer of his wallet to his new computer, which was acquired during the Christmas holidays.
He had the hard disk of his old computer wiped. And so had his password manager where he stores his passphrases needed to access his private wallet keys unchecked.
Onnar gave details of how he had already done encryptions as backup of his private keys on two USB drives stored in separate locations. Then he plugged one of the USB drive into the computer to confirm if everything was properly done, only to find out later that it wasn't so.

Onnar admitted that a ledger device would be more suitable to help in handling his Bitcoins, he never imagined that at that time his own methods weren't safe enough.
The Bitcoin owner made a mea culpa of the incident, then admitting that he didn't know that his passwords weren't auto-saved in the manager