An estimated 21 million Bitcoin is irretrievably lost. I have contributed to that number.
I first began using Bitcoin in 2012 when a college friend insisted that it was the future and tried to get everyone else he was friends with to use Bitcoin, only send signed and encrypted emails, and to use Tor for any sort of web browsing. I think everyone else eventually gave up or refused to do some of the things.
I was in Bitcoin early enough that I was with MtGox— and lost some Bitcoin in the MTGox hack. Anyway, my only retail transaction was spending a little over 1 BTC on a bag of 9 1-gram metal elements (It was fun to look at how much thicker the aluminum was compared to the lead.) and 1 gram of silver, because silver was not included in the aforementioned element bag. After that, I stopped paying much attention to Bitcoin.
When I noticed in 2021 that BTC was topping US$60,000, I decided it was worth trying to sync up my old wallet and possibly selling my BTC. I had a wallet on one computer that had stopped syncing for some reason. I did not make a new back-up of this wallet.
I went to a retired computer and set up Bitcoin Core with my wallet back-up. I had one place value less of bitcoin than I had on the computer that stopped syncing even after the blockchain was loaded.
Why did this happen?
According to my research after waiting futilely for my BTC to go to its original quantity…
When you make a Bitcoin wallet, you do have a set address. However, when doing the transactions, a certain number of addresses are also generated. These are used as you do transactions. Once all of these additional addresses are used, more are generated. However, when you back-up your wallet, it saves the current additional generated addresses.
To avoid this being a problem, you need to back-up your wallet regularly.
And actually use that recent back-up when reloading your wallet.
