My mom took me to the YMCA for swimming lessons when I was  kid in the 60's.  She had to wait in the lobby for me. It was all-men, and they swam naked, or wearing only a jock strap. A bit intimidating to a nine-year-old.  I wore a swim suit, as did the other boys and our instructor, but the rest of the pool was full of naked men jumping in and out or doing laps.  The lessons were pretty minimalist and after about three days, we were expected to jump or be thrown into the deep well, and swim across the diving well to graduate. I failed, miserably, just too tense and afraid of immersing my face and eyes in the burning, chlorinated water. I was so self-conscious in the locker room I put my pants on over my wet swim trunks and tried to walk out that way, just to get out faster.

A few years later, we were living in the suburbs, now I'm about 13. Outdoor suburban pool, co-ed, 70's. Took lessons with the park district lifeguards, and it was better, a slower paces with more one-on-one training, but somehow I still didn't quite get it. I would be good for a couple of strokes and then just had to stand up. But I loved going to the pool every day in summer, since it was about a hundred yard walk from my back yard. On my own, about a month after flunking the park district course, it just came to me, and I found I could relax a bit, stretch out my limbs, and my body *wanted* to float. Floated on my back, floated while dog paddling... and  then I managed the breast stroke and crawl, with my head out of water the whole time.  Practiced swimming for a day or two, then told my parents I had figured it out on my own. They didn't believe me, I had to demonstrate it, with my sloppy form, paddling around the deep well for about ten minutes. But yes, I could swim. It was all about having the confidence and taking my own time, then relaxing and realizing I could float.