If I had spare time, one thing I would love to study would be the histories of monies and currencies, and how they intersect and diverge.
Precious metals have traditionally been used as stores of wealth because they are tangible, perceived to have more utility and value than other items, and can be fashioned into uniform units that could easily be exchanged, weighed, and scrutinized for authenticity.
An ounce of gold, silver, and copper, is still an ounce no matter the shape and form.
In the late Roman Empire, inflation took the form of using a lower percentage of precious metal for each unit of coinage.
In modern times, coins are minted with rigged edges to discourage coin clipping.
If the US Dollar was to collapse, it would be interesting to see what would replace it as an exchangeable store of wealth in the United States and Globally.