I have to agree with you regarding commas and conjunctions. I was taught 60 years ago that a comma is not necessary when a conjunction is used. A, B and C is correct to me and I would have to have a English PhD tell me otherwise.

FWIW, I learned it the same way you did, and that's the way I write it.

I laughed when I read Fred's comments regarding serial commas. While I don’t cringe when I see them, I’ve always done it using two commas. My guide in such matters is The Chicago Manual of Style, and it says, “In a series consisting of three or more elements, the elements are separated by commas. When a conjunction joins the last two elements in a series, a comma is used before the conjunction. One of the examples given seems appropriate: “We have a choice of copper, silver, or gold.”

As the editor of the Royal Canadian Numismatic Association’s electronic bulletin, NumisNotes, I am in Mr. Fred Michaelson’s corner on the use of the serial comma. I follow the conventions of the Chicago Manual of Style, 16th ed., and it is clear on the issue. Here is the relevant article for everyone’s edification:

6.18 Serial commas Items in a series are normally separated by commas. When a conjunction joins the last two elements in a series of three or more, a comma—known as the serial or series comma or the Oxford comma—should appear before the conjunction. Chicago strongly recommends this widely practiced usage, blessed by Fowler and other authorities, since it prevents ambiguity. If the last element consists of a pair joined by and, the pair should still be preceded by a serial comma and the first and (see the last two examples below).

She took a photograph of her parents, the president, and the vice president.

Before heading out the door, she took note of the typical outlines of sweet gum, ginkgo, and elm leaves.

I want no ifs, ands, or buts.

Paul put the kettle on, Don fetched the teapot, and I made tea.

Their wartime rations included cabbage, turnips, and bread and butter.

John was singing, Jean was playing guitar, and Alan was running errands and furnishing food.

However, I acknowledge every editor’s privilege to “interpret” the rules.