If some people has lots of bitcoin in their offline wallets and they die or lose memory.
Then those coins will be out of circulation right? Or is there any way to recover them?
That will still be considered in circulation I guess but definitely not the case in the actual world because it is already forgotten. If the owner who died did not write a will or even some sort of note for his or her family member to become aware of the treasure, then the bitcoins will forever leave this world with him. I don't think it can still be recovered.