Someone once asked...
Someone answered with kindness...
Invest in the stock market, duh.
Another soul answered...
I would get healthcare. I'm currently living with an untreated autoimmune disease in a country that doesn't guarantee free healthcare. So I'm trying to make money so I can get treated at least. And ultimately, having unlimited money wouldn't eclipse my goals because my goals are only enabled by money, not made of it. That said, ambition can only take you so far. Maybe having limited means limited time and limited health is the bayonet that deserves to be at your back? After all, would we be running slower without them? Probably.
Another soul answered...
Create a hardware key that is meant to be an anonymous national ID for the internet. It would be verified via a signature chain so that each person gets their key signed by a local notary. And those get signed by the state. And the owners can only be tracked down with paper or offline records.