Bottle caps.
Coca-Cola had a promotional campaign in the Dallas area. All of the bottle caps on Coca-Cola products that had a football stamped on the outside had on the inside a head shot of either a Cowboys player or an NFL star. From participating stores, you could get a map-size sheet that had corresponsing spaces on which to glue each bottle cap. When the sheet was full, you could take it to the Coca-Cola Bottling Company office in Dallas and trade it in for a new football.
My mother -- a saint -- would take me to all the convenience stores in the area, and I would talk the store clerks into emptying the bottle caps from their Coke machines. In those days, when you bought a soft drink from a machine, there was a bottle cap opener on the machine. The caps fell into a bin for later disposal. The clerks would empty those bins into my brown paper bag, and I would sift through all the bottle caps to find the ones that had the football stamp.
I filled the sheets -- two of them, actually -- and my brother and I got new footballs.
The NFL players were impressive -- John Unitas, Bart Starr, Y.A. Tittle, Deacon Jones, whomever -- but the guys who I wanted were the Cowboys. Not just stars like Don Meredith and Don Perkins, Bob Lilly and Frank Clarke. I wanted the Don Bishops, the Mike Gaechters, the Mike Connollys, the Jerry Tubbs, the Don Talberts, and on and on.
I had the Cowboys roster memorized when I was so young that I can't recall any specific games. All I knew was that these guys were important, that they were football players!
The Ice Bowl cost me my football virginity.