I remember the exact moment I made the promise. It was a Tuesday afternoon, and my best friend Liam was packing up his desk for the last time. His family was moving to Queensland at the end of the week. We had been friends since kindergarten, and the thought of not seeing him every day made my chest feel tight. As we walked out to the pickup zone, he looked at me with watery eyes and said, "Promise you'll write to me every month." I nodded and shook his hand. "I promise," I said. That handshake felt heavier than any test I had ever taken.

For the first few weeks, I kept my promise easily. I wrote him a long letter about the new soccer coach and how our class had adopted a guinea pig named Nibbles. I even drew a cartoon of our old classroom. He wrote back quickly, describing his new school and the beach near his house. But as the months passed, homework and cricket practice started to fill my afternoons. One month I forgot to write. Then two months slipped by. I told myself I would write next weekend, but next weekend never came. The guilt grew like a knot in my stomach.

One night, I found the shoebox where I kept Liam's letters. I pulled out the first one and read his excited words about making a new friend. Then I saw the last line: "Can't wait for your next letter!" My face burned with shame. I had broken my promise. I grabbed a pen and paper right then, even though it was past my bedtime. I wrote about everything I had missed — the school fete, my little sister's first steps, and how much I missed our lunchtime chats. I didn't stop until my hand ached.

I wrote him a long letter about the new soccer coach and how our class had adopted a guinea pig named Nibbles.

The next morning, I posted the letter before I could change my mind. A week later, an envelope with Liam's handwriting arrived. Inside was a single sentence: "I knew you'd keep your promise." That letter taught me something important. Promises are not just words you say when things are easy. They are the things you do even when it is hard. I still write to Liam every month, and I have never missed one since. Keeping that promise made our friendship stronger than ever.

Looking back, I realise that the promise I kept was not just about writing letters. It was about being the kind of person who does what they say they will do. That lesson has stayed with me through every friendship since. When I make a promise now, I think of that shoebox full of letters and the relief I felt when I finally wrote back. Some promises are hard to keep, but the ones you keep are the ones that matter most.