Amnesia is a standard device for establishing scenarios with indexical uncertainty, to reassert the fact that your mind is in the same state in both situations (which is the essence of indexical uncertainty: a point on your map corresponds to multiple points on the territory, so whatever decision you make, it’ll get implemented the same way in all those points of the territory; you can’t differentiate between them, it’s a pack deal).
Amnesia is a standard device for establishing scenarios with indexical uncertainty, to reassert the fact that your mind is in the same state in both situations (which is the essence of indexical uncertainty: a point on your map corresponds to multiple points on the territory, so whatever decision you make, it’ll get implemented the same way in all those points of the territory; you can’t differentiate between them, it’s a pack deal).