My grandma grew up on a farm. She went to a one room schoolhouse through the 8th grade. She led a rather sheltered life.
When Grandma was 16, her older sister, Wave, had a job in town working for the telephone company. One day she took my grandma in to work with her. After a time, she asked Grandma to go over to the local store and buy a bottle of milk for them to share with lunch. Wave gave her the money and told her to hurry back.
Grandma was terrified her sister was making fun of her. Milk didn't come in bottles; everyone knew it came from cows! She was afraid she would ask for a bottle of milk and the sophisticated city folks would laugh at the simple country girl, just like anyone would laugh at a man asking for a left-handed monkey wrench.
Imagine her surprise when she asked for a bottle of milk and it was handed to her, she paid for it, and took it back to the phone company!
(I remembered this story because my mother asked ChaCha where milk came from and Cha answered, "The store.")