i always sorta feel like when people say their character has amnesia, what they mean is that they're too lazy to write. which, even that's fine--the best RP is completely improvised.
the real way to do amnesia right is honestly to make it very clear that you're not using it as an excuse to avoid writing. all of the plot points of their life should exist. just because the character doesn't remember what happened, doesnt mean there's no physical evidence of what happened. maybe someone else knows your character's past. maybe they get brief glimpses of memory. there should also be a solid reason why they have amnesia.
the real way to do amnesia right is honestly to make it very clear that you're not using it as an excuse to avoid writing. all of the plot points of their life should exist. just because the character doesn't remember what happened, doesnt mean there's no physical evidence of what happened. maybe someone else knows your character's past. maybe they get brief glimpses of memory. there should also be a solid reason why they have amnesia.