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.
Bear in mind that logically, the longer time goes on and the more you interfere, things will diverge. You might only be able to win the lottery a handful of times before the butterfly effect starts giving you numbers which don’t match your predictions from the future. I figure the same thing happens with investments. If someone buys a tonne of shares using billions, the history of the stockmarket will change and over time be unreliable outside of certain events. Might be wise to buy up aquire certain talent though.
make your billions by buying lots of small, but super profitable investments.