You likely decided to come here again, and to forget again, since that is part of it.
Had you remembered who caused you harm in your last lives, or that you were the opposite sex, or the terrible things you may have done, if everyone had these memories, we'd probably all be at each other's throats right from the get go.
If enemies forget that they are enemies, they might have a little peace as they start again, and a chance to complete lessons amongst each other when otherwise it would just be a prolonged war.
The way things are, two enemies can switch sides and beat each other up thinking they are right this time.
Imagine the surprise when they die and see the big picture.
I likely did not decide to come here and forget again. I'd suggest you go back and read my early posts regarding my thoughts on the veil, as well as my resistance to coming back.