I think that this is confusing domain applications of concepts (algebra, abstraction in mathematics) and the same concepts in everyday speech. Everyone gets Proper nouns as variables and understands stories where the two people get their brains swapped. (Identity of objects as behaviour, memory addressing or duck typing)

so, I think most people get writing and symbols involved and that stories carry most of the functions needed for even reasonably complex programming

and that's without teaching children lisp from an early age

There are a class of programming models that exploit that, and they aren't very expressive. At best, they are suitable for casual programs who need to write some code to solve very specific problems, say writing something in Excel. However, serious programming (done by full time programmers) really requires the ability to create new functions.

What's a new function if not "have a bath" or "bathe quickly in the river" - apart from math specific definitions ?