To the class of 2013:

Refill the ice cube tray.

You’ll receive a lot of advice in the coming weeks, from parents, teachers, siblings and classmates, but the best of it can be boiled down to those five words. You’ll be told to follow your dreams, to take chances and to make a difference, but none of that hits on the one immutable rule of living on this planet.

Refill the ice cube tray.

You are graduating into an uncertain world. There is political and economic turmoil across the globe. Regimes are falling, or taking drastic measures to hold on to power. Population growth and climate change are increasingly threats to the world’s resources, particularly food and clean water, and there is little will to address them.

Locally, the news isn’t much better. The cost of providing the K-12 education you just received is steadily rising. Taxes are being raised to keep pace, but wages are staying put. Every year, the bills grow larger, but the pay does not.

These are problems handed to you by your predecessors, too many of whom never thought or cared to refill the ice cube tray. Instead, they went to the freezer, emptied the tray, and put it back in, leaving only a few scattered chips for the next person.

That won’t change overnight, but it can change, person by person, day by day, starting with you, the class of 2013. Wherever you go next – on to college, or into the workforce or military – you’ll have to make your own way. You’ll have to show up on time, put in your best effort, acquire the necessary skills and perform in ways that open up opportunities and allow you to reach your goals.

Above all that, however, is the realization that your life is part of a greater whole. Your body, your brain, your choices – you own those. But you do not own life, you revolve around it. It is something you take part in. It is something you are obligated to contribute to.

This is a contract too often ignored. We are too into our own lives, our jobs, our bills, our phones, to acknowledge the strangers around us, and that they, too, are revolving around life, in their own orbit. We don’t have time, or simply can’t be bothered, to recognize the impact of our everyday actions on other people. Once we have our ice, we find it difficult to remember that someone else may need it, too.

So make it your priority to put more into life than you take out, not only through charity and hard work, but also in each of those tiny interactions, at the grocery store, in your car, while getting coffee.

Refill the ice cube tray, and do your small part for a better world.

Ben Bragdon is the managing editor for Current Publishing. He can be reached at bbragdon@keepmecurrent.com or followed on Twitter.