I find kindred observations from many here and @Tygerscenthas substantial Venn diagram with my pre and even post puberty home life. We grew up skinny dipping with friends and family; that persisted even after we moved away when we were back at our parents’ farm on a weekend or other occasion. There was no a/c in the early years so sleeping on top of the sheets, without a stitch of textile on our bodies, was how summer nights were passed. As the saying goes, you don’t know what you don’t know until you do. Thus it wasn’t until I had a roommate in the university dorm that I had the slightest inkling of how differently another male, living in an intimate setting (if memory serves the dorm room was like 300 sf) , can have an expectation of otherwise unattainable privacy. I was not without compassion, he had hideous acne that covered the majority of his body, but it was difficult to adapt his covered up approach to dorm living as what should be normal for both of us.
My experiences in the gym communal showers, the locker room, the sauna and steam room have all varied from one end of the spectrum to the other. So often the vibe of a particular brand or space is a decisive factor. The university space was young boys loaded with testosterone, thinking about any number of things from a girl they liked the looks of to is my penis above, below or just average as I note the physiques of such a volume of naked bodies all in one place, a totally first time experience for so many.
Post school life has similar experiences when first joining a new gym and wanting to seem like a regular the vibe has to be observed or sensed. The YMCA is often a different flavor than an Equinox; Golds different than a NYSC or LA Fitness and within those franchises the flavor varies from NYC or Dallas or Boston to an Austin or Nashville. Established versus new or newish and hip. Point being the experience one had as a reference for what is not going to get anyone excited in one locale may not translate into another locale.
In the final analysis you can only be who you are even if that makes you an outlier on occasion. Often being who you are is the breath of fresh air others come to appreciate first and then emulate.