Hmm...what if you were a stream enterer in your previous life and now a returner??? Of course, you don't remember it. Does it mean you have to become a stream enterer again? How does this work on an experiential level??? I assume not but your level of your illumination penetration "should be" more greater and advanced......in this life.
Yes you have to become stream entrant again by realizing the nature of dharma, realizing the emptiness of self.