I laughed when I read about a Dutch entrepreneur attempting to legally change his age in order to enhance his career and dating opportunities. He reasoned his current age of 69 didn't correctly represent his "emotional state." Instead, an age of 49 would better reflect who he was, he said.

With this being my birthday month, his antic got me thinking that he does have a point. How old we think and feel ourselves isn't always aligned with how long ago we were born. In fact, research confirms there's truth to the axiom: "You're only as old as you feel." A recent study found that subjective age, the age we feel we are, can affect how we age. It notes that "those who feel younger than their age actually do show fewer signs of brain aging."

Ever since my mid-40s I've felt at least twenty years younger than my chronological age. While I know I'm long past living in the "land of the young," as author Chip Conley calls it, I also know I don't relate to the AARP market or desire to live in an over 55 community.

As I add another year to this life's journey, I'm thoughtful about the word "old." I know "old" people half my age. In every generation -- Matures, Boomers, GenXers, and Millennials, you'll find old people: old thinking, old acting, old being. Old isn't a certain age, and getting older isn't a choice we're given, but whether we get old or older, often is.

My yardstick is simple: I'm just getting older if I'm excited to get up in the morning, awed by nature, find wisdom in past struggles, read the travel section, learn and try new things, meet new people, stay relevant, love loving, and find my life's to-do-list growing.

But I'll know I'm old when I stop reading the New York Times, give up on dreams, become a passenger in my life, think more about yesterday than tomorrow, stop watching new movies and embracing new technologies, only do what I've done before, and never throw a snowball.

Yet a decade ago, I thought it was enough to understand evolving versus stagnating as separate aging concepts, and choose the first; to welcome each year as a gift denied to many and a reminder of life's finiteness. I used to think we'd grow old if we gave up our dreams, so it was enough to keep pursuing them, but some dreams expire and should be given up or changed. Now, I understand that growing old and growing older are more complicated than any pithy philosophy or personal intentions might declare.

In the scheme of things, while my outer packaging has changed through the years, I wouldn't trade my decades journeying life's pathways for renewed youth. Life can be profound, heart-breaking, overwhelming, challenging, delightful, and exuberant certainly. Some years and decades are better than others, But like an older river that flows more gently then a new one, I find I've come into an age that's completely unattached to a number. For me, it's an age of discovering what really matters, after all. And the good news? You don't have to wait to be my age to find yours.