The one thing all humans have in common is that each of us wants to be happy, says Brother David Steindl-Rast, a monk and interfaith scholar.

And happiness, he suggests, is born from gratitude. An inspiring lesson in slowing down, looking where you’re going, and above all, being grateful.

“We all know people who have lots of misfortunes that we ourselves would not want to have, and they are deeply happy, they radiate happiness,” he says. Why are they like this? “Because they are grateful. It is not happiness that makes us grateful, but gratefulness that makes us happy.”

So how exactly do we live gratefully? ”By becoming aware that every moment is a ‘given moment,’ as we say,” Steindl-Rast explains. “It’s a gift. You haven’t earned it or brought it about. And you have no way of assuring there will be another moment given to you.” As such, we should consider each moment as precious and a great opportunity. “If you didn’t have this present moment you wouldn’t have any opportunity to do or experience anything.”

So what about that saying, “opportunity knocks only once.” Not true, says the good brother. “Think again. Every moment is a new gift.” Miss the opportunity of one moment and another one will be right along. “The master key to our happiness is in our own hands. Moment by moment we can be grateful for this gift.” It’s a beautifully simple but powerful thought.

Watch his speech at TEDGlobal 2013.