I worked in a small hardware store in college and the store manager was a woman. There were a couple of guys she had hired because they were specialists, but she knew more about hardware in general than all the rest of us put together (and she was the Boss on top of that).
It was always funny to watch people's faces when we didn't know something and called her over for help.
I can't even remember how many times she would give a detailed and accurate explanation and the customer would still turn back to me like they wanted me to confirm it, even though I had just called her for help.
I was a barely-trained part-timer, but I'm a guy so they just assumed I knew best.