Sometimes, I feel like I missed something — something big and important, like the secret to life, or the key ingredients to a life well lived.

This probably has something to do with getting older and coming to terms with just how challenging life can be. Indeed, if one thing has become increasingly apparent in my 30 years of existence, it is that life is hard.

I suppose I should have realized this when I received a college graduation card from one of my uncles that read, humorously: “Stay in school as long as you can. The world is a cold, cruel place.” But, as I’ve come to learn and relearn time and again, experience truly is life’s greatest teacher.

In fact, it would take a decade of journeying through the ups and downs, challenges and disillusions of myriad academic and career pursuits for me to grasp one of the most basic, universal life truths: there exists nothing outside of us that is capable of producing the lasting contentment we long for as human beings.

“The ultimate source of happiness is within us,” the Dalai Lama states in The Book of Joy. “Not money, not power, not status…outward attainment will not bring real inner joyfulness. We must look inside.”

In a culture that promises fulfillment in nearly everything “out there” – conditioning us to measure our success, value and worth by a resume of accomplishments and credentials – it can be quite disconcerting to realize that our tireless pursuits will never fill the void that exists within each one of us, a marker of our human imperfection.

And yet, this revelation – that we have within us all the joy, love, peace and fulfillment we desire – is nothing new; it has been heralded as one of life’s most essential truths by countless gurus and teachers throughout the centuries, a call to claim responsibility for our peace and contentment.

Buddha, the master of Enlightenment from the 6-4th centuries B.C., said: “With our mind we create our own world.”

The ancient Greek philosopher Epictetus (50-135 AD) wrote: “We cannot choose our external circumstances. But we can always choose how we respond to them.”

And Jesus Christ, arguably the most influential person in history, declares in the Gospel of Luke: “For behold, the kingdom of God is within you.”

Yet, somehow, I feel like this knowledge – an ancient wisdom that illuminates the way to inner contentment, and which seems so obvious and achievable – remains rather elusive, particularly when the messiness of life presses into us.

Indeed, I only began to grapple with this truth recently, and rather reluctantly, when I could no longer make sense of my life. Having graduated college magna cum laude, fulfilled my childhood dream of living and working in New York City, studied as a grad student at the University of Edinburgh, and nearly enrolled as a Master of Divinity student at Princeton Theological Seminary, I was slowly forced to confront an underlying discontent, realizing that the more I tried to seek fulfillment in my achievements, the more unfulfilling my life seemed to become.

But, perhaps that’s the point, part of the beauty – that we come to a greater understanding of life’s truths when we need them most, often when our plans or strategies fail us and we’re in need of a new approach for navigating the tumultuous roads of life.

The beloved author Anne Lamott writes in her most recent book, Almost Everything: Notes on Hope: “It’s ridiculous how hard life is. Denial and avoidance are unsuccessful strategies, but truth and awareness mend.”

As I leave behind my twenties filled with memories of both triumphs and challenges, I find myself grateful for all of the experiences that brought me to where I am now, entering the decade of my thirties a bit wiser, a bit more knowledgeable, and a bit more aware of an ancient wisdom I can now call upon when times get tough.

So maybe I didn’t miss anything after all. Maybe we can never expect to fully know the secret to life, but can learn to receive wisdom along the way – truths that can heal and mend, allowing us to experience a fuller, more wholesome life.

As St. Ignatius of Loyola, founder of the Jesuits, once wrote: “For what fills and satisfies the soul consists, not in knowing much, but in our understanding the realities profoundly and in savoring them interiorly.”