Perhaps the entire schooling system? Even now, most people seem to believe it is broken or deeply flawed. Definitely one of those legacy systems in need of an update.

I also think that under a Bitcoin standard, debt will be far less common to the point of sounding crazy. Very difficult to pay off your dues in a deflationary environment, and there will be no printers for reckless borrowers.

Oh and people collecting shiny yellow rocks as a store of value. :^)