My theory is that men are autistic. Men have the Collecting Bug more than women. It is men that spot trains, men that fly off to the Isles of Scilly on the basis that someone may have spotted a Rufous-sided Towhee, men that obsess about batting averages, men that need a complete collection of Autosport, men that cream themselves over an unused block of Penny Blacks.
When I was young I collected Panini football stickers. Like most of the boys in my class. The average album seemed to have about 544 stickers. It took most of the season to complete. Obsession. Introspection. Autism.
The girls had sticker albums too, Smash Hits ones or ET film ones. They had around 100 stickers and it took about a week to do. Lack of dedication. Or better things to do.
There are some exceptions, and the whole thing is about comparing maybe 10% of the male population to 2% of the female, but it is IMO a major difference between the sexes. I mean, women actually throw away magazines. I don't even throw away the airline freebies.
I am guessing that at some point in the distant past Ug the caveman was keeping statistics of which of his Neanderthal tribe was the best at hunting. "Noop got 3 rabbits today, but Klog got a bison, which puts him into 4th place, a woolly mammoth and a partridge behind Ekko. Skag is only outside the relegation zone on foal difference."