butter comma peanut

Who decided peanut butter should come first?
What reasoning led to this order?
It is not alphabetical
Unless it was decided by a librarian, butter comma peanut ampersand jelly
Librarians, beautiful minds all, are not the natural arbiters of sandwich naming conventions

It is not historical, the origins of both lost in the mists of time
Though let us explore that concept
Once upon a time, neither existed, no butter comma peanut, no jelly
I would pause for a moment of silence here, sad as the thought of a pre-PBJ world is, but you might think I was finished and applaud so let us press on

At some point in antiquity someone dug up, roasted, salted, and crushed the cotyledons of Arachis hypogaea
And it was good
Someone, was it someone else or the same someone, mashed berries containing a sufficient quantity of pectin and, perhaps they forgot them on the counter, and it jelled into, well, you know
And it was good, too

But which happened first?

Fine, I said origins, mists of time, et cetera
But fruit is easy to find
Peanuts, not so much
Fruit is obvious, over time becoming sweeter, and mushier, with no help from Homo Sapiens
Peanuts, not so much
What with the digging (why?) and the roasting (why?) and salting, which I get, but crushing, again why?
Jelly is obvious, likely, spontaneous, inevitable
Peanut butter, not so much

And yet
If someone were to offer you a jelly and peanut butter sandwich
Or, in fact, a jelly and butter comma peanut sandwich
Or even a sandwich comma jelly ampersand butter comma peanut
Would you trust them?
Would your taste buds tingle?
Or would that be the hairs at the back of your neck?
Because whatever the origins
Or not so much
Even a child knows
Peanut butter comes first
(except, dear librarians, in the dictionary)