Comment by ZackOfAllTrades

You are totally right. For somebody like me who did learn from W3 initially though, those first class functions are conceptually and in practice "inline" functions. If you are talking to somebody who knows the difference between inline functions and first order functions, then you probably don't need to tell them to learn more about how to use higher order functions. But if first class functions are conceptually the same as "inline" functions to a person, then they would probably benefit from the advice to learn more about higher order functions. How would you suggest explaining how to handle an event without using the word "inline"? Explain how functions are first class and go from there?