I'm going for the default answer of "it depends" I think the situation of Amnesia is actually more preferred in situations where you're having trouble pinning down a back story or need to buy time to read up on lore and I've done this a few times before with previous and current characters, Ellmida is a good example of this actually, where all her memories prior to the calamity are vague and blurred together.
I personally have no issue with amnesiac characters save for situations where it's just used as a half baked contrivance for some quick drama, as in if it's treated as a serious situation which is automatically improved with little explanation why. As for how my characters deal with these types..... depends on the character.
In situations with year old characters, I think it can be done even for a retcon but I would think you would have to take more care than with characters that were brought in with it, probably better in situations where those you usually do with are not currently playing to mess up the retcon with... Knowing you.
I personally have no issue with amnesiac characters save for situations where it's just used as a half baked contrivance for some quick drama, as in if it's treated as a serious situation which is automatically improved with little explanation why. As for how my characters deal with these types..... depends on the character.
In situations with year old characters, I think it can be done even for a retcon but I would think you would have to take more care than with characters that were brought in with it, probably better in situations where those you usually do with are not currently playing to mess up the retcon with... Knowing you.