Understanding dormant wallets for beginners

[Zaguru12]

To be honest I don't think there is a way to know if some coins are really lost, because the owner could retrieve his private key one day even if he is not hoping it anymore.

I also second this, as along as a coin in this regard it s sent to a valid address that’s a valid private key. Even if the owner of the private key actually losses that key it is still not a lost coin to me but rather an unmoved coin, that can coincidentally be moved should the private key is found. An exception of sending a coin to a valid address and it should be considered lost will be when that address is time lock for a thousand or million years and that still mathematically is not considered lost again.

The only way to consider a coin lost is when it is sent to an OP_RETURN output, this script is locked and can never be unlocked. The coins here are even said to be removed from supply. So I think they are qualified to be called lost coins

[Saint-loup]

No, I disagree with you, if someone is able to sign a message from an adress it means he's still owning the private key and he's still controling the address and the funds belonging to it. So if someone does that, you shouldn't believe them and you should consider those coins and this address as not lost instead.

Perhaps he was trying to say that a person could sign a message using Address B in which they say that their coins in Address A are lost. But even that is wrong, as it now becomes a thing of trust. Anyone can make such claims, and you still can't prove it's real. You can either trust that the signed message is true or not.

Well if a guy signs a message from an address A saying the coins sent from the address A to the address B are actually lost, because he made a fat finger mistake or because he knows the owner of address B and he's now dead for example. I wouldn't trust him at all. And if he owes me money I wouldn't take it as a valid excuse. Eventually, if he made a multi-inputs transaction with address A and address B together in the past, I would listen his story, but I wouldn't give him all my trust freely either regarding an actual loss.

[Pmalek]

But I said "almost" nothing. The longer the time with no activity, the higher the probability to be lost forever. The problem is that apart from those coins which were "burned" you can't know for sure which ones are lost or not.

Less than 10 days ago we had outgoing transactions recorded on an address from satoshi's era. No tags should be put on addresses regardless of how much time passes since the last time they were used. It's my right not to use my bitcoin for a day or a decade if I want without anyone speculating what's wrong with me, am I still alive, have I lost the keys, etc. I have even seen suggestions of removing coins from old addresses and somehow putting them back into circulation. That's ridiculous. It's stealing and it's no longer bitcoin but a centrally controlled lookalike.