Tina writes:

¤The average person does not know how to use a circular slide rule.
The average pilot does, The private pilot must solve wind triangles, a
form of vector analysis, must demonstrate some skill in navigation,
enough gas theory to understand the dynamics of weather systems,
enough physics to know about lapse rates, and so on. The average
person does not.

All of these skills are trivial and largely unrelated to those I mentioned.