We are now in an era when there are far fewer opportunities for males to see the cocks of other males. In years past, there was absolutely no privacy in public restrooms, school locker rooms, etc. There was even naked swimming at the Y.
But today, there are few chances for males, of any age, to see the cocks of other males. Even in families, there is much less use of shared restrooms, among fathers and sons and brothers.
So, the truth is that many young guys have grown up without seeing very many cocks of other males, of any age.
And since size is such a "big deal", whether or not it should be, they do wonder about the size of others, and if their size is "normal".
I believe we should return to the old days, when males of all ages were naked together in a variety of settings, and boys had the chance to see the great variety of sizes and shapes, even of foreskins, among other males.
Young males, especially, grow up with the real NEED to look at Cocks! If they are denied this opportunity during their formative years, it will be a problem for them throughout their lives.