Many Founders dream of building a unicorn: a startup valued at over $1 billion. Such a beast in business is rare, mythical, and nearly impossible to create. Unfortunately, many people who create unicorns also risk killing them before their companies reach their full potential.

I’ve worked with enough Founders to know that success often starts with an almost irrational level of confidence and aspiration. The best founders believe in something before anyone else does. They see an opportunity where others see risk, and they push forward when others would be tempted to hesitate.

But there’s a fine line between driving a company forward and driving it off a cliff—and I’ve seen too many founders miss the warning signs. I refer to this as the fine line between vision and insanity.

Why Do Some Founders Self-Destruct?

The downfall of a promising founder follows a predictable pattern:

1. They start by doing everything themselves. In the early days, there’s no choice. They must make every decision, close every deal, and solve every problem.
2. They experience early success. Customers, investors, and the media validate their vision. Their confidence skyrockets.
3. They stop listening. Advisors, employees, and even market signals take a back seat to their gut instinct. They believe they’re always right.
4. Then, they often push too far, too fast. Expansion outpaces reality, financial discipline crumbles, and when the reckoning comes, there’s no safety net.

WeWork’s Adam Neumann wasn’t wrong about the demand for flexible office space. But he overextended, burned through cash, and ignored the fundamentals of running a sustainable business. When the bubble burst, it took billions in investor money with it.

Theranos’ Elizabeth Holmes wasn’t wrong about the need for faster, cheaper blood tests. But instead of pausing to ensure the technology worked, she doubled down on a fiction. Investors bought the story, not the product. The result was criminal fraud charges and a collapsed empire.

What brings down Founders who fly too close to the sun? I believe it’s almost always vision without self-awareness.

The Most Overlooked Trait of Successful Founders

The best Founders are aware of their own shortcomings and the realities of the marketplace.

One of the most disciplined founders I’ve ever worked with built a wildly successful company. He knew the industry inside and out—but he also knew when to step back.

Instead of clinging to control, he brought in private equity. He took money off the table, kept a minority stake, and stayed on as an advisor. He recognized that scaling the company required skill sets he didn’t have—and rather than letting ego dictate his next move, he made the smartest decision for the long-term success of the business.

That’s the difference between a founder who builds something that lasts and one who becomes a flash in the pan.

How to Avoid Killing Your Unicorn

If you’re a founder, ask yourself:

1. Are you listening to your advisors or just waiting for your turn to speak?
2. Do you truly understand your company’s financials, or are you trusting that someone else has it covered?
3. Are you making decisions based on long-term strategy or chasing growth at any cost?

Founders don’t fail because their ideas are bad. They fail because they don’t recognize their own blind spots. Some figure it out. Others don’t.

And then there are those like Elon Musk, who somehow manages to walk that tightrope without falling.

Read more on Elon Musk’s leadership here.