Chocolate milk cartons were for fancy schools.
We had to bring our daily "milk money" of 0.15 for a pint carton of plain white milk. Amd we had to take our own "bag lunch". PB&J or Bologna (Oscar Meyer, of course).
Ours was a tiny private (catholic) school in Lincoln. The nuns had normal names and dressed normally. Just "sister <whatever>". But in the early 70's, we had laser scanners in stores. Then we moved to the east coast in mid 70's. It was like stepping into the dark ages for me. Manual cash registers. No drive through tube's at banks; you had to go in or use the window. Nuns wore habits and had guy names (Apostles). On the other hand, inside some of the old trees around us were the remains of musket shells from the American revolution. Which is kind of cool for a kid who's interested in history
Nothing like playing kick-ball on the Princeton Battlefield. And it really was.