Consider something we use every day but don't think about unless, of course, we lose them: keys. They lock doors, turn on cars, keep valuables safe. More poetically, they can open minds and hearts.
Writer Helen Oyeyemi has been thinking a lot about keys. In fact, she's written an entire book about them, What Is Not Yours Is Not Yours — nine short stories (she says she could have written 900) about the power of keys.