This afternoon, after the students had gone home and my classroom was empty and quiet, I got to thinking that everything that happened in the room today was gone. The words we spoke, the activities we did together, the smiles and frowns we shared – all of these seem to have disappeared like smoke. Twelve thousand teaching and learning moments appeared to be gone forever. I felt like I had been floating on a strong river all day long, through all my classes, and now, at 3:45, the river had vanished, never to return. Another river would flow tomorrow, but today’s was nowhere to be found. It made me somewhat sad to realize this, but before long, luckily, I had another, opposite realization – that, in a sense, nothing that happened today in my classroom would ever disappear. All the ideas that flowed along through my room from first period to last would never vanish, because they are not made of a substance that can vanish. Ideas and words are not material things that can fade away and die out. Once created, they begin their magical work of altering lives, and this work never ends, no matter how concealed it becomes. The river that ran through my room today may appear to be gone, but it’s only slipped into a hidden realm where it will continue to run its miraculous operations. Without realizing it, my students and I will be quietly affected, in thousands of small ways, by every thought and word that was shared in Room 2 today. The briefest comment by the quietest student will ripple through all of our lives in ways we can never imagine. And the same marvelous thing will happen again tomorrow.