> doing the groceries
Is there a shortage of groceries? Are people hoarding? Are they just 'bad people' or does a rational person change what they buy during a shortage? Why? Would you expect a Government saying "don't hoard" to have any effect?
> playing a musical instrument
Is there an orchestra you want to join? Will a particular instrument get you in the door easier than any other instrument?
> sport
Soccer. Why do you see so many obvious dives in professional soccer? Why do grown men hold their shins and cry when the replay shows they weren't hit?
Sumo. When a sumo wrestler is one win away from a promotion in a tournament, and he's facing an opponent who has already guaranteed his own promotion, what are the odds the first sumo wrestler will win?