Do I de-age, or am I just moving to a previous point in my timeline as I am today? If I do de-age, do I at least keep all my knowledge and experience intact?

If so, I would love to go back to my pre-schooling childhood, power through the "child genius" phase at record speed, and get some good investments started early (Microsoft, Google, Apple, etc.) so I can speed-run my retirement and live better than I currently am. Heck, since my young spongy brain absorbs knowledge much easier than my current adult brain, I could work to earn a few doctorates in STEM fields while I'm young and then try to improve the world once I reach adulthood.

I retired last year at only 38 years old (military pension, plus disability pay), but it's basically kept me in the same place I started out. I moved back into my childhood house and I have enough passive income to just relax and enjoy my life. So I'm essentially back to my childhood life, where I'm just doing whatever I want every day without worrying about monetary cost.

But it'd be nice to have the money to build my childhood dream home (Modern castle/fortress with hidden rooms and passages, completely self-sustaining and off the grid, on 100+ acres of private land). And I would like to pay off all debts of my closest friends and family. (REAL friends - the ones who were good to me before they knew I was wealthy)

I'd also like to be rich enough to be a philanthropist who can just throw millions at fixing major injustices in the world. Like, Elon Musk could literally end world hunger if he wanted and he'd hardly notice the impact to his finances. But he doesn't give a shit, so the world continues to suffer under megalomaniacs like him.