Sakuya Kira: It's really more of a misnomer. Social or collective amnesia really refers to the idea of a group of people forcefully repressing memories as opposed to accidentally forgetting memories. Individual amnesia usually occurs through an accident or some kind of trauma, physical or emotional, the magnitude of which is unusual to happen to large groups of people.

[He presses enter and immediately regrets; he entered Academic Mode there and didn't think to edit before hitting submit. Stupid. The last thing he wants is for someone to figure out who he is...]

Sakuya Kira: anyway, u get the idea
Sakuya Kira: amnesia the way we usually think about it's pretty unlikely to happen to a group of ppl
Sakuya Kira: how forgetful?