All these pursuits are commonly perceived as a bit eccentric or cranky, and anyone trying to explain what makes their hobby so fascinating might well be in danger of reinforcing that view! I don't necessarily agree.
Coins have been a central part of everyday life for centuries. Given a few minutes I am pretty confident I can convince most folks that studying and collecting them can be both worthwhile and cool.
The sharp trend away from cash transactions (presumably there's some quantification of this out there) is a dark cloud on the horizon, but the history remains.