Yellow school buses. Fresh haircuts. Crisp, clean spiral notebooks. New names laminated on old desks. Moms and Dads and tears in elementary school parking lots. Nervous teenagers at awkward lunch tables. The early morning crack of football helmets. Marching bands practicing fight songs. These are the things of August. As memories, they are palpable because of our history, because of the hope we place in education and because of the power of teachers.

As the son of two lifelong public school teachers, the start of each new year always comes in August, not January. Much more powerfully than turning over the calendar to a new year, the beginning of school each August brings forth promise, excitement, hope and, yes, a little nervousness for everyone involved.

On a recent mission trip to Peru with my daughter, we witnessed something I won’t soon forget. In a very concrete way, I was reminded of the power of teaching. As our construction crew poured footers for brick walls and dug holes in the Peruvian desert, we watched a 12-year-old girl at the home next door go through the same routine each morning. Living by herself in a home with dirt floors, no running water, no electricity and thatch walls that couldn’t withstand even one gust of Texas wind, we saw her emerge each morning at 9:30 sharp wearing a freshly pressed uniform and with a perfectly clean, brightly colored backpack thrown over her shoulder so that she could walk two miles to school. She lives by herself five days a week because her parents are forced to travel back into the heart of the Andes mountains each Sunday afternoon to care for the crops and livestock that provide the only livelihood they’ve ever known. She lives by herself because there are no schools in the mountains. She lives by herself so that she can have opportunities her parents never knew. She lives by herself because of the power of teachers.

I’ve spent the last 25 years teaching and studying and writing about education. At no time in our nation’s history has committing oneself to a life of teaching been more difficult. The pay is unacceptable, students are more distracted than ever and too many political leaders offer nothing but vacuous praise, especially each time an election cycle rolls around. One prominent 20th-century American educator, William C. Bagley, made this last point quite powerfully when he challenged us (in 1918, no less) with the following questions: “When will the public cease to insult the teacher’s calling with empty flattery? When will men who would never for a moment encourage their own sons to enter the work of the public schools cease to tell us that education is the greatest and noblest of all human callings?” A century on, we seem to have made little progress, even gone backwards, I would argue.

One lesson that I learned many years ago continues to ring true. It provides grounding whether the subject is third-grade math, 10th-grade history or college piano. In the midst of caustic political rhetoric and futile quests for pedagogical panaceas, teachers need a lifeline. They need a rope that will never break. They need a foundation that will never crumble. To the army of heroes who will step into classrooms this August and face another set of nervous students, I offer this: When the classroom door is closed and it’s just you and them, give your students who you are and what you know. Not half of it. Not some of it. All of it. Nothing else matters.

Wesley Null is Vice Provost for Undergraduate Education and Institutional Effectiveness at Baylor University. His books include “Forgotten Heroes of American Education, American Educational Thought and Curriculum.” He can be reached at Wesley_Null@baylor.edu.