I was four. At that time, we lived in Windsor, Ont., Canada. My dad would take my brother and me swimming at the old YWCA in Windsor. It was all male on Fridays. This was during WWII. We were absolutely not allowed to wear swimsuits. There were men and boys from babes to those in their 80s in the pool all naked.
Ever since, I've been into casual nudity whenever possible.