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.
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.
If you have never seen it, you should watch the British television show Red Dwarf.
There is a character named rimmer who is dead and has been brought back as a hologram.
Relatively early on in the series, through some Star Trek fuckery he manages to bring another version of himself back and begins to cohabitate with himself.
Aside from that, if you even reasonably like science fiction or comedy then it’s a damn good show to watch. It’s been running for 12 or 13 seasons, it started back in the '80s, and as far as I’m aware there is another season scheduled to be released.
“Smoke me a kipper, I’ll be back for breakfast!”