In this episode of The Making Of, Jack Pitts sits down with Gary Dennis, co-founder and former CEO of Mammoth Holdings, to unpack how a kid from Macon, Georgia ended up building one of the leading car wash platforms in the country.

Gary walks through his path from humble beginnings — with a dad who was a maintenance mechanic and a mom who was a secretary — to Georgia Tech, an MBA from Vanderbilt, and an early career in equity research and investment banking. He shares how getting humbled by a boss during his college co-op and by money managers on Wall Street shaped the way he thinks about work, preparation, and actually understanding the numbers.

From there, Gary breaks down the jump from a comfortable investment banking career into owning and operating car washes. He explains:

• How a “side hustle” idea turned into Mammoth’s first self-serve wash
• The trip to Louisiana that exposed him to the express wash model
• Why he thinks of car washes as manufacturing plants, not retail
• What the 2008–2009 downturn and months of nonstop rain did to the business
• How a mispriced early subscription product almost flopped — and the data that helped them finally get it right
• Taking site-level break-even from ~7,000 cars a month to zero with memberships

Gary also talks about building Mammoth into a true multi-state platform through development and more than 30 acquisitions, why their internal rule was “no jerks allowed,” and how they structured deals so great owner-operators could roll equity and stay involved.

Finally, he reflects on partnering with institutional capital (including the Pritzker Organization), stepping back from the CEO role after nearly 20 years, staying involved as chairman, and how he now splits his time between board work, investing, his alma maters, and advocacy around long-term housing for adults with developmental disabilities.

If you’re thinking about leaving a “safe” job, scaling a gritty real-world business, or just want an honest look at the grind behind a 20+ year “overnight success,” this conversation with Gary is worth a listen.