Functional leaders exist in every company. Each department and team has someone in charge who's making sure everyone is operating effectively.

But the buck stops with the CEO.

People tend to envision the job of CEO as the most enviable position in a company. While you can find a lot of fulfillment by taking on that role, you also have to understand there are dramatic differences between your assumptions and the reality you'll face.

The skills you need are different. The expectations change. And while your experience as a leader will serve you well, it's really just the starting point in a constant process of learning and personal development.

Here's what to expect when becoming a CEO:

You realize it's impossible to always protect your team.

Part of being a functional leader is protecting your team's morale and ideas. You inspire, mentor, lead--and you protect. When you become a CEO, you quickly learn there will be situations where you can't protect everyone.

Back in 2014, our team at ThirdLove built our own front end and back end for our website. And to be honest, it was a poor move on our part. The website was crashing, we didn't have basic e-commerce features, and we were diverting our attention from what we really wanted to do: create a great product and ensure our customers had a top-notch buying experience.

My co-founder and I made the decision to start using a Web platform service to support our company online. A lot of our engineers disagreed with the choice.

As leaders, we felt we really had to push forward--regardless of how people felt. It ended up being the right decision. We're still using that platform to this day, and the change allowed us to scale. But it wasn't easy.

When push comes to shove, you have to be willing to make the hard decisions--and be OK with doing what's best for the company instead of a single team.

You understand the importance of different leadership styles.

Good leadership is about recognizing where your blind spots are and where you're strongest.

CEOs have to take this assessment a step further. Being at the top means understanding your own leadership style and the different types of leaders around you.

If you're unsure of your own style, you can use a tool like the DiSC method to figure it out. Once you do, you'll begin to understand how you work best--and how the people around you fit into that dynamic.

For instance, I tend to lead by influence. That means I'm more comfortable inspiring people, asking them questions, and letting them reach a conclusion on their own.

But influence is by no means the only way to lead. Sometimes, you just need to get things done. You can't dive into a 30-minute discussion to get people on board. They may not agree, but it doesn't matter. You have to tell them what to do, and they need to do it because you're telling them. Right now.

I'm not as comfortable with that type of leadership. But it's important for me, and any CEO, to realize when it makes sense. The sooner you can understand both the strengths and pitfalls of your leadership style--and the leadership styles of those around you--the better your chances of success.

You discover how to use and understand your intuition.

Leaders usually have a gut instinct about their situation. You may be interviewing a potential hire or making a difficult decision, but that little voice in the back of your head is going to pipe up at some point.

It's absolutely essential you learn to trust your intuition.

The problem is, it's harder to do that when you become CEO. It can seem awkward or uninformed to say, "This is how I feel about it," rather than relying on cold, hard data.

But honestly, some of the worst decisions I've made as a CEO came from not listening to my intuition.

There have been a few times when a person looked great on paper but I felt something wasn't quite right. Each time we hired that person, my doubts were realized. They weren't the right fit, and we had to let them go.

Your intuition isn't going to be right 100 percent of the time. But there's often a reason why you get that gut feeling about a person or situation. At the very least, you'd be wise to explore it before making a decision.

Understanding these nuances is just part of the transition from a leadership position to CEO. Truthfully, there will never be a time when you can look around, dust your hands, and think, "That's it. I know everything I need to know."

There's always a skill you can be honing. One of those is learning how to thrive in the differences that set you apart.