Hey, thanks for reading and commenting.
To clarify, when I'm talking about the generation gap when it comes to nudity, I'm not just talking about getting naked in a locker room. I'm around five years younger than you, and I too have no trouble getting changed in the locker room. However, I'm only naked in the shower itself, and for the ten to twenty seconds it takes me to dry off and get changed at my locker.
These old men, though? They will spend several minutes straight just hanging out without any clothes on. I'll wrap a towel around my waist as I'm heading back and forth from the shower; these old men will walk back and forth with their towel hanging over their shoulder. Zero fucks given about the dozen plus people they're walking past as they do this. It's a level of confidence in their bodies I simply have not seen in anyone younger than forty.
I'd say most young people, after they get past high school at least, don't have a problem getting changed in the locker room. They just aren't comfortable being exposed for more than ten seconds at a time, whereas the older men will just wander around naked without a care in the world. That's the generation gap I'm seeing.