Graphene. That stuff is expensive as heck to produce at the moment, and expected to be useful in a ton of future technologies.
Mind controlled nanobots, I’m about to be emperor of the world.
Weed
Pizzas. The parties I would throw…
Saying “bills” is dumb. Bills have no realistic value above what we name it.
Saying “diamonds” isn’t smart because they’re actually very abundant.
So, gold is a safe choice. It will never lose its value provided I don’t, you know, crash the gold market or anything.