You could probably measure someone's age how hanging his balls is.
Saw a pixelated naked Mario with his dick hanging out or his balls. Some guy commented "it happens with age". Had me thinking if someone posted someone's balls online you could probably guess his age how saggy it is.
No. I use changing rooms regularly and see the balls of various men. Some younger than me have saggy balls and some older have tight balls. I don't think ball sagging can be linked to age so rigidly sufficient that you could guess the age with any accuracy.
the balls are attached to the people, so you can't really miss them if they're naked whilst changing or in a shower. 2) I don't have my own personal changing room, so other men will be there. 3) what?