Think back to the organisation where you spent your first serious years. The way decisions got made. The kind of people who got promoted and the kind who didn't. What counted as a good idea and what got quietly ignored. The unspoken rules about how to handle conflict, how to present to senior leadership, how to read a room, how to survive.
You were absorbing all of it. Not consciously, not through training, but through the most powerful learning mechanism available to human beings: immersive, high-stakes, socially consequential experience. You were watching what worked and what didn't, filing it away, building the mental models that would eventually become your instincts.
That process produced something genuinely valuable. Hard-won judgment. Pattern recognition that no MBA programme can manufacture. An intuitive feel for people, organisations, and dynamics that takes years to develop and cannot be shortcut.
It also produced something more dangerous: a set of assumptions so deeply embedded that you have almost certainly stopped noticing they are assumptions at all.
The Operating System Problem
Every leader operates on two levels simultaneously. The visible level is the one you are aware of — the decisions you make, the strategies you set, the way you show up in rooms. The invisible level is the operating system underneath: the foundational beliefs about how organisations work, what motivates people, what good leadership looks like, which risks are worth taking and which aren't.
The operating system was largely written in your first ten years. And here is the problem: operating systems are not designed to be questioned. They are designed to run silently, efficiently, and without interruption. The better they work, the more invisible they become. And the more invisible they become, the harder they are to examine — let alone update.
Most leaders, if pressed, cannot tell you with any precision what their operating system actually contains. They can describe their values and their style. They can articulate their strategy and their priorities. But the deeper layer — the tacit beliefs about human nature, about power, about what organisations are actually capable of — remains largely unexamined. It just runs.
“The operating system was largely written in your first ten years. And operating systems are not designed to be questioned.”
Where It Came From
The first organisation you worked in seriously was not neutral. It had a culture, a set of incentives, a theory of how business works. That theory may have been sophisticated or crude, healthy or dysfunctional, well-suited to its era or already quietly obsolete. You absorbed it regardless, because that is what people do when they are young, ambitious, and trying to understand the rules of the game they have just entered.
The boss who taught you how to read a boardroom — what did they believe about authority? The mentor who showed you how to manage people — what were their assumptions about trust and control? The first crisis you navigated — what did it teach you about risk, about loyalty, about who shows up when things are hard?
These experiences did not just inform your thinking. They became the template against which all subsequent experience was measured. Later organisations, later bosses, later crises were all filtered through the lens that the first decade ground. Confirming evidence reinforced the model. Disconfirming evidence was often rationalised away — because that is what mental models do. They protect themselves.
For many leaders, the first decade took place in a world that was genuinely different from the one they operate in now. Different information economics. Different workforce expectations. Different competitive dynamics. Different assumptions about what an organisation is, what employees want from it, and what leadership is actually for.
The world changed. The operating system didn't.
“The world changed. The operating system didn’t.”
The Competence That Conceals the Problem
What makes this particularly difficult to address is that the leaders most in need of examining their operating system are, typically, the most successful ones. And success is the enemy of examination.
If your first-decade mental models helped you build a career, lead organisations, and deliver results — and they almost certainly did, or you would not be where you are — then those models come with a powerful endorsement. They worked. The evidence is your career. Questioning them requires a willingness to interrogate the very foundations of what you believe made you effective. That is an uncomfortable place to go voluntarily.
It is also genuinely difficult to distinguish between the elements of your operating system that remain sound and those that have expired. Not everything absorbed in the first decade needs to be rebuilt. Some of it — the understanding of how power actually moves in organisations, the ability to read people under pressure, the judgment about which problems solve themselves and which don't — is genuinely durable. The work is not wholesale demolition. It is the harder, more precise task of working out what to keep and what to retire.
The Rebuild Starts With an Honest Inventory
The first step is not learning anything new. It is sitting with a question that most leaders find quietly destabilising: what do I actually believe — about people, about organisations, about leadership — and where did those beliefs come from?
Not the beliefs you would articulate in an interview or write into a leadership philosophy document. The operational beliefs. The ones that show up in the decisions you make when time is short and stakes are high and nobody is watching particularly carefully. The ones that determine who you trust instinctively and who you don't. The ones that shape which information you seek out and which you discount. The ones underneath the ones you know about.
That inventory is uncomfortable. It requires a kind of intellectual honesty that senior roles do not typically reward — the willingness to say, about something you have acted on for twenty years, that you are no longer certain it is right. But it is the only starting point for a rebuild that actually changes how you lead, rather than simply adding new vocabulary to an unchanged foundation.
The first ten years built more than you know. The question is whether you are still living in that building — or whether it is time, finally, to examine the structure and decide what needs to come down.
What You Absorbed in Your First Ten Years Is Still Running the Show