If you’re a teacher, or love a teacher, or even know a teacher, you may have an idea why Katie Pearson, 1st grade teacher at Blue Haze Elementary School in Fort Worth, TX, cried five times the other day.

You may know the load teachers carry as they fight the pressures of standardized tests and evaluations and budget cuts. And the heartache they feel as kids slip through the cracks or face neglect and abuse at home.

You may know that they don’t get paid anywhere near what they deserve for the hours of love and sweat and, yes, tears, they pour into their classrooms. For the energy and dedication they pour into their students—our babies.

As a former teacher myself, I know. I know about the crying days. The days when you don’t know if you have it in you to keep going (you do and you will). But then, as you slump into your chair, tears falling on a pile of papers to grade, a child hands you a box of Ziploc bags.

And you find yourself crying, again, but this time with pride. Because you know you’re doing this teaching thing right, despite the test scores and complaints from parents and attitudes from students and political bureaocratic ugliness that you want to escape but permeates your building’s hallways. You know that you’re helping these tiny people turn into good grownups.

Pearson says she cried several times in one day recently because of the weight on her shoulders. “You feel if not everyone of your kids leaves reading and writing on level…that you have done a disservice to them,” her post reads. “You feel like you not only failed your students, but the parents, the next teachers, the administrators, etc. You feel like a failure because you didn’t read every day with every student (which is impossible). You feel like a failure because not every student showed huge academic gain. You feel like you shouldn’t be a teacher because your classrooms academic data doesn’t look like the classroom across the hall. You feel like you have set a kid up to fail because they didn’t read a non fiction level 16 with the proper comprehension and text to self connection. You feel the weight of their future on your shoulders.”

That weight can crush you if you’re a teacher.

But then.

Then, one day, a student hands you a gift like this one, and you know the truth of the impact you’re having on the world. On your students’ world.

“Miss Pearson, before Christmas you said you were out of ziploc bags at home,” her 1st grade student said to her. “I saw your sandwich and chips in the same bag. Nobody needs that. That’s gross. Plus, when we need something, you get it. When we lose our glue, you may not be happy but you get us another one. Or when Joe* eats his pencils, you tell him it’s wrong but you still give him more. You told us that if we love people, we show them. You said real leaders show people. I just want to show you.”

Now we are all crying.

“Sure, the world needs better readers and writers….but our world really needs softer hearts, eager hearts, and willing hearts,” Pearson writes. “Our world needs kids who observe more and learn from it. Our world needs more compassion. So my kids may not all be on level when they leave me…but they all leave me knowing they can be better and that they have the potential within to make this world better.”

It was in this moment that this exhausted teacher of 20-something impressionable, young, innocent children realized what really mattered. And although, of course, it’s important that her students learn to read and write, what will truly change the world is not their reading level.

“I’d rather have a class leave with a heart that loves others than with the ability to read a DRA 16,” Pearson says. “Because those ziploc bags mean more to me than an entire class on grade level. Anyone can teach them to read but not everyone will teach them to care.”

This is it right here. This is the stuff. This is what it means to be a teacher. And as a mom of three children in elementary school, I say thank you, to Ms. Pearson and to all of America’s educators. Thank you for teaching our kids how to read and write and add and subtract and where Africa is and how to make volcanoes blow up. But most of all, thank you for helping us to raise good humans who will be kind to one another. Who will take care of one another. Who will care when they see suffering and who will step up and do the right thing.

Ms. Pearson, I hope you enjoyed your sandwich the next day with your chips in a separate bag. And I hope you can carry the love and appreciation from that sweet child with you on your worst days to remind you, once again, of what really matters in the end.