What “The ONE Thing” Taught Me About Mastery, Habits, and Clarity in Coaching

I picked up The ONE Thing by Gary Keller thinking it might offer some productivity tips.

What I didn’t expect was a mindset shift.

This book isn’t just about doing less to achieve more—it’s about purpose. About clarity. About understanding what truly matters, and then orienting your life—and coaching practice—around that truth.

In our latest episode of The Coaching Book Club Podcast, I shared how this book challenged and supported me, not just as a business owner but as a coach on the MCC path. Here are a few reflections I’ve been sitting with since that conversation.

Mastery Is a Mindset, Not a Milestone

Keller writes:

“Mastery isn’t a word we often hear anymore...but at its core, mastery is a way of thinking, a way of acting, and a journey you experience.”

That line stopped me.

I’ve spent so much time thinking about the MCC as a destination—something I “arrive at.” But what if it’s not about arriving at all? What if mastery is something we practice rather than achieve?

This shift reminded me of ICF Core Competency 2: Embodying a Coaching Mindset. For me, that looks like celebrating the small steps, noticing the missteps, and continuing to reflect even when no one’s watching.

Because that’s the path. And it’s worth walking with intention.

Habits, Not Willpower, Drive Real Change

Another insight that hit home:

“When you see people who look like ‘disciplined’ people, what you're really seeing is people who've trained a handful of habits into their lives.”

How often do our clients come to us saying, “I just need more discipline”?

This book helped me reframe that. It’s not about grit or hustle—it’s about alignment. What habits support the version of you you’re becoming? What routines reflect your values?

In coaching, we get to help clients name those habits—and design lives that support them. We facilitate client growth(ICF Core Competency 8), not by pushing harder, but by scaffolding smarter.

Knowing Your “ONE Thing” Clarifies Everything

For me, my ONE thing is learning.
It’s the through-line in my coaching, my business decisions, and the way I show up for clients. Knowing that grounds me.

And when I share it out loud? It builds trust.

When we can name our ONE thing, we model transparency. We’re not just helping our clients get results—we’re helping them get clear. And that clarity connects deeply to ethical, aligned practice (ICF Core Competency 1).

Progress Is the Next Right Step

“You do the right thing and then you do the next right thing. Over time it adds up.”

I’ve been repeating that to myself lately.

As coaches, we don’t have to map the entire path. We just have to help our clients find their next step—and then the one after that. That’s how real awareness happens. One small shift at a time (Core Competency 7: Evokes Awareness).

This book gave me language for what I already believed: that meaningful change isn’t flashy—it’s layered. It’s iterative. It’s deeply personal.

How I’m Using This in My Coaching Practice

Since reading The ONE Thing, I’ve been using one powerful question more often in my coaching conversations:

👉 “What’s the ONE thing that matters most right now?”

It cuts through the noise. It brings our attention back to purpose.

And when a client says, “I just don’t feel disciplined,” I don’t coach them toward more force—I coach them toward better alignment. What habits would feel energizing? What routines would actually serve their real goals?

This book also gave me permission to slow down in my own journey. As I work toward my MCC, I’m no longer just focused on the credential. I’m becoming the kind of coach who’s grounded, clear, and present—because that’s who I want to be.

A Final Word

The ONE Thing reminded me that clarity is a kindness.
To ourselves.
To our clients.
To the work we do.

When we stop trying to be everything to everyone—and instead root into what matters most—we build a business (and life) that feels like home.