Children's minds exhibit remarkable creativity, even when it comes to self-discipline. So it's good on multiple fronts that many children have loving mothers who know not only how to watch over their offspring while cultivating their independence, but how also to retain tenderness and a sense of humor no matter what unusual solutions their children concoct to life's conundrums.

In this true story based on author Carlos Matias' 1990s childhood, Ernesto's mother gives him a quarter on the first day of school, his first walking the six blocks to school without his parents. "For emergencies," she whispers to him. "If you need me, look for a pay phone."

In those days, as Matias explains in an opening note to readers, cell phones were rare and "luckily, the streets were peppered with pay phones — these were public phones that we could use to call our loved ones for just twenty-five cents."

Ernesto is mightily tempted to use that first quarter after school to buy baseball cards when his friends spend their more lavish allowances at a Señor José's bodega. But he holds on to it — for emergencies — and he manages to hold on to his Tuesday, Wednesday, and Thursday quarters, too, even when similarly tempted by arcade games, tropical fruit juice that reminds him of summers back in the Dominican Republic, and a tamale from Doña Tania's tamale truck.

We haven't had a chance to test this book out with its four-to-eight-year-old readership to see if they'd find what happens on Friday as funny and endearing as we did — but how could they not? For now, let's just say that there's nothing better than a parent's unconditional understanding.

Matias' flair for storytelling shines brilliantly here and is perfectly matched with Ezra Jack Keats Award–winning illustrator Gracey Zhang's vibrant captures of life in a bustling city neighborhood. We won't stop smiling over this book for a long time to come.