He must understand that buying real-estate is an investment, buying stocks and bonds is an investment even buying a car can be an investment.

Buying bitcoin on the other hand, is NOT an investment.

The reasoning behind buying bitcoin is NOT to make money off it (not an investment), IT IS money.

It's also a technology, a monetary system, a payment network, a store of value, a zapping tool and was also considered a commodity by the US government.