If I were informed that last night I had suffered a horrible pain, all memory and other traces of it having been erased, I would be scared that this might happen again, but the unremembered pain would be almost as nothing to me. All's well that ends well. On the other hand, if I learned that one of my children had suffered a horrible pain last night, though all memory and other traces of it were erased, I would not only be scared that this might happen again, but I would feel very sorry for the child for having felt that pain. I would be glad it ended well, but the ending wouldn't be all.
It's as if I were a presentist about myself and an eternalist about others. This is some evidence for eternalism, I think. For it is likely that moral attitudes towards self are a special case, to be taken care of by indexical-type considerations, while it is moral attitudes towards others that are a better guide to the objective order of the world.