Culture isn’t something entrepreneurs typically think about when starting a business. They’re focused on products, services, markets, and profits—but rarely on the intangible force that shapes their organization’s future.

Yet businesses, organizations, and teams are fundamentally human, and humans are inherently complex. Our beliefs, mindsets, and opinions don’t just influence our interactions—they dictate how effectively we collaborate, innovate, and succeed.

Culture is the unwritten rulebook. It’s the “this is how we do things here” statement that’s communicated not through official guidelines but through daily actions, reactions, and decisions.

Creating a strong, vibrant culture isn’t accidental. It’s deliberate. It’s purposeful. And it starts from the top. Every leader sets the cultural standard—not just through declarations or motivational speeches but through their actions and behaviors. When leaders tolerate mediocrity, it becomes the norm. When excuses are routinely accepted, accountability vanishes. When issues are ignored or minimized, they grow unchecked.

Early in my career, I experienced firsthand how critical these principles are. When I was running Blu Maya, my customer experience agency, I made the difficult decision to fire a business partner who suggested an idea to a client that contradicted our core values. Similarly, at Netek, I removed a co-founder who habitually belittled our development team during my absence, undermining the culture we aimed to uphold.

These weren’t easy decisions, but they were necessary. By acting swiftly and decisively, I demonstrated that our cultural standards were non-negotiable. Each decision sent a clear message to our teams: we practiced what we preached.

If you want to build or transform your culture, start by clearly defining what you expect, then live those expectations consistently. Because culture isn’t what you say; it’s what you tolerate.

Bottom line: Creating and modeling culture is a leader’s most important job. You have to be intentional every day. Those who don’t will have a hard time changing it later on. Remember, you get the behavior you accept. If you want excellence, stop tolerating anything less.