A childhood belief about sport

There's a building that my family would always drive by, but never actually visit, that said "Pool" on the front window.
As a child I didn't know any other meanings of a "pool" other than a swimming pool, so naturally, I thought it was a pool for people to swim in. Whenever we drove past it, I would ask my parents if we could go to the pool place. They always said no and told me that children weren't allowed in there. I was always confused as to why I wouldn't be allowed to swim in a pool until I was an adult. So for a long time, I assumed the reason why pool halls didn't allow children was because everyone had to go naked to swim in the pool.