What are the three toughest words for professionals to utter? It's probably not what you're thinking. It's simply, "I don't know." The economics team of Stephen Dubner and Steve Levitt, authors of "Freakonomics," have studied this idea of how not being able to utter these three simple words actually costs U.S. industry and business millions of dollars annually from people committing big mistakes.

Who wants to admit ignorance? As it turns out, not many. But successful, intelligent, creative and highly effective managers want to admit ignorance. They also want to admit to making mistakes, the kind of mistakes from which one learns. As Mark Twain famously said, "Personally, I learn from every mistake, and I intend to die a genius."

As facilities executives, we have learned a lot, but in reality we all know that we just can't know it all. Some of us might be gifted in one area and fall short in another. Some of us might be mechanically disinclined but make wonderful strategic thinkers and managers of our team(s); others might know every part and piece of large chillers or electrical distribution systems. All of that is good, but a pinky doth not make a hand.

I would not have the experience and confidence I have today if not for the mistakes I've made (some colossal), and learning from those mistakes makes it easier for me to look somebody in the eye and say either, "I don't know," or "I'm not sure." When I tell people I don't know something, I almost always qualify it with "but I will find out ASAP."

I also don't punish people on my staff who make honest mistakes, especially when they are centered on careful and calculated risk-taking. Risk-taking is something I appreciate as a manager — calculated, intelligence-based risks.

As I've made my mistakes and admitted to my ignorance, I've also been careful to look for gaps to fill. Knowing that I can't actually "know it all," I've learned that I at least need to learn enough to "know what I don't know."

What does that mean, "knowing what you don't know?" Do you have enough knowledge to find the right adviser for an area where you're lacking? Can you admit ignorance in an area? Do you have enough understanding of the many situations and challenges that cross your path to form a plan for how you'll solve the problem or challenge with outside resources?

As a leader of my organization and as someone who is expected to manage and balance the challenges of my organization, I am constantly resharpening my saw. I'm also setting an example for my staff. Look for ways to improve and enhance your skills. Don't be afraid to risk trying to learn something new — stretch yourself.

Resharpening that saw is also retaking or staying current with something you might think you've already mastered. As a manager, I really don't like it when one of my staff or a consultant tells me, "We've tried that before, and it doesn't work."

I always wonder, did they try hard enough, did they forget a step or key part or component? I also wonder who was spearheading that initiative when they tried it or has the technology changed? I think, if you tried back then it couldn't have been that bad an idea, right?

If I retake courses and relearn things that I've already completed and passed, I'[m making myself a better decision-maker. Even if I don't work in the actual area I'm studying, I'm learning how to ask good questions and recognize gaps. Relearning components of your job and new skills are good because, as I stated earlier, technology and methodology are constantly changing.

Perhaps the sting from those previous mistakes resonates more with me, and I feel a need to be as sure as I can be to not relive that feeling. I'm not sure. But I know it feels good to be able to keep up with the plethora of consultants and experts that I deal with in any given week at work. I'm not saying I can outpace them — note I said, "keep up."

I'm committed to being a life-long learner, and I admire that same commitment in others. I will go out of my way to advance people on my staff who show a commitment to constantly learning, stretching their abilities and a willingness to take risks.