Assume that the future can change based on your actions, so any historical information that you bring along with you from the intervening 25 years may quickly drift out of the new realities history.
Edit: also assume that you can be given a healthy 21-year-old body if you want or take your previous self’s place.
Further, identification will be provided for you if you were not born at that time.
I have some crazy news for you. Not everyone is 21. Believe it or not, but there are people who are older than that (I’m one of them! Boo!)
I misread OP. I was under the impression that you reset as a 21 yo