It would probably be possible to pass your memories over to another astral being, which would in turn make you remember your old self. Or maybe even possible to be so in harmony with your subconscious to teach it that it would remind you itself upon your next life. That is what hypnotists do to remind people of their past lives, aye? So why can't you make an agreement with the subconscious to do so in the future. Isn't that who stores all the information you gathered before, and unlocks it when you are given clues(any information?)?