A difficult subject becomes more welcoming when the first examples feel reachable.

The first example decides who thinks they belong. Open a hard subject with something that assumes prior exposure and the people who happen to have it feel clever, while everyone else concludes the door was not really open to them. That has nothing to do with aptitude. It measures what somebody met earlier, and it sorts a room within two minutes.

Choose your opening example for how reachable it is rather than how well it shows off the subject. Use something ordinary that a person can hold in their head. Save the elegant case for later, when it will be a pleasure rather than a filter.