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.
If a bunch of you’s from another timeline can come too, that opens the door to more interesting shenanigans anyway, like if they all get unique valid IDs, one of you could run for political office and get enough alternative selves to come back and vote for them to win. Or get different versions of yourself to run for all the political offices in a given area while bringing enough copies to win all their elections, and completely dominate the politics of the area by having everyone in office have the same or very similar views.
The downside here is I’d have to spend all my time with other me’s. I’m pretty sure I’d get on my nerves very quickly.