It is such an uncomplicated, simple word. The one-syllable just rolls off the tongue with alacrity.

Yet, to speak this word keeps us awake all night, can ruin a career and may terminate personal and professional relationships.

“No” chills our soul because of its finality. The dye has been cast, the writing is on the wall and the barn door has been closed in the wake of “no.”

It is my opinion healthy, assertive people must become comfortable with “no” in order to succeed. There are four good reasons why “no” should be part of your vocabulary.

First, “no” is endemic to the practice of creating boundaries.

In order for us to protect our minds, bodies and futures it is essential we know how to build fences. There are just some internal places in us where only invited guests are permitted access.

Here are questions all of us must answer as we develop maturity over a lifetime. “Will my chosen profession, with all its demands, drain my physical energy and deplete my emotional warehouse in order for me to be a success?” “Is there someone in my personal life who is emotionally holding me hostage?” “Can I control my need to consume?”

From choosing to eat one donut instead of four and working 70 hours a week for the next 20 years, we all have to stake out boundaries. “No” is the first and last word when stringing barbed wire around our psyche.

Second, “no” clarifies expectations from those around us.

I find it much easier to work with someone who can be consistently honest with me about what to expect in the future. If I have to constantly second guess whether or not this person is “really” committed to a project, working relationships become confusing and often problematic.

The real problem in working relationships with someone who cannot utter “no,” is they will use silence and delay to make decisions. These are the folks who do not return phone calls, respond to e-mail messages or sit in a conference room and nod approval but everyone knows they are wandering around in another galaxy at that moment.

Third, when you say “no” you authenticate your value as a strong and worthy person.

We live in a “yes, yes” world. Whether we are in a drive-thru lane talking to a faceless microphone or in a doctor’s office giving approval for recommended tests, we socially feel the pressure of a “yes.”

We consistently hear, “I think you will have to agree with me….” Or, “This is an opportunity you just cannot turn down because we offer this product just once a year….” Or, “Come on, honey, we may never get to see Paris again in our lifetime….”

Personal value is determined, not just by what we do, but who we “are.” Our character, who we “are,” is brushed out on a life’s canvas with the integrity of our agreements and our “no’s.”

Finally, verbalizing “no” leaves room in life for…you.

We are interdependent people. We have to rely on each other to get food on the table for dinner tonight, finalize an agenda for a team meeting tomorrow and turn in accurate numbers to the IRS.

But there has to be a few moments in our life when we become “intradependent.”

If we are saying “yes” to every request there may not be the space or time for us to get comfortable with “me.”

I meet people all the time who are angry with…themselves. They sulk around seething with regret that life has become a large stadium where the crowds just keep screaming demands and they are out of breath rushing from one new goal to the next.

Saying “no” can disappoint and even create anger in those who watch your life from a distance, but “no” also says “yes” to direct and nurture the life you know best…yours.