Twenty-eight years ago, I raised my right hand and took an oath to defend the Constitution of the United States. Twenty-eight days ago, I took off my Army uniform, put on a business suit, and joined McChrystal Group. From the battlefield to the business world, helping a new employee develop and become a leader of her peers is what I love to do. I love challenging myself and others to be better at what we do. That’s what sparks joy in my life, and I’d imagine it does for many women in business.

I’ve been asked by soldiers around the world, “What’s the one thing I should know to be a better leader?” My answer remains the same: Know who you are, your strengths, and your weaknesses. Self-awareness will be that “extra something” that boosts you up the corporate ladder.

As we move up the ranks in our careers, our technical skills are usually the primary reason we get promoted. We closed the most deals or sold the most product. But as we develop as leaders, functional excellence is no longer the main component required to be high-performing and succeed as a senior leader. Self-awareness plays a much more prominent role.

We’ve all worked for “that” boss. He/she made a lot of money for the company—a real mover and shaker. And then they got promoted. Unfortunately, for those on the team, this new boss doesn’t have the necessary leadership skills to lead them. What went wrong? Why didn’t the successes of the past lead to success in the new environment? In my experience, it came down to self-awareness.

Self-awareness is that critical skill that will help influence how you relate to others, how you communicate your guidance, and how you process input from others. Self-awareness underpins all that we do. It’s the difference between good and great.

Don’t get me wrong: We all have bad days. But as you move up the corporate ladder, your bad days soon have a much larger influence in creating bad days for others. I saw this on the battlefield when senior leaders were tired, hungry, and missing loved ones. I was that leader in some cases. I didn’t realize how much influence my lack of self-awareness had on others. It took mentorship, patience, and development to grow into a more self-aware leader.

And I continue to see it across the business world. Those leaders who soon recognize that their own behaviors and emotions have a domino effect on their team—and adapt accordingly—build stronger teams. Self-awareness is that “combat multiplier” that not only makes you a better leader, but those on your team better leaders, too.

It took years of practice and wasn’t easy. I continue to remind myself of the importance of self-awareness. And I thank my mentors and McChrystal Group teammates for continuing to challenge me on this leadership journey. Ask a friend or co-worker how self-aware you are. Trust me, they’ll know.