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.
Also, start generating Bitcoin in late 2009 and sell it all on Nov 10, 2021.
Sell it when it’s in the 10,000 range the first time, circa 2015, then buy back when it drops to 400 in late 2016 and then hold
It spiked to 17,000 in 2017 too, if I recall.