Whether it is no, nein, non, Nyet, or 番号, every language has a way of expressing “I am unable,” “I’ll pass,” “sorry—I don’t want to,” or even an emphatic “fat chance.” Yet I believe that the simple word no, when properly used, is one of mankind’s most beautiful expressions. I would argue that no is a word we should hear more often to save us from a lot of grief and frustration.

In 1983, at the height of the Cold War and a mere three weeks after the Russians had shot down a Korean Airlines 747 full of passengers, a Lieutenant Colonel in the Russian Rocket Force by the name of Stanislav Petrov, quite unexpectedly to say the least, noticed alerts flashing on his early warning screens. Could this be true he thought? Could the Americans actually be executing a nuclear first strike against Russia? Could this handful of missiles be the opening salvo of a much larger attack?

Fortunately for the entire world, Stanislav Petrov concluded that what he was seeing on his screen certainly must be a mistake—for if the Americans were indeed launching a massive attack, wouldn’t they be sending hundreds of missiles toward Russia and not just five or six?

Petrov’s cool thinking led him to deliberately disobey standing orders to immediately report such a warning to his superiors. Of course, he later filed the necessary paperwork, but in the heat of the moment he, in his own way, said “No” to the established authorities and the rules.

This was not just some odd event from 40 years ago and it is not an exaggeration to say that this man might have single-handedly saved the world. For what would the top-level Russian leaders have done with a report that enemy missiles were on their way to cities and military bases inside the Motherland? Would someone at that top level have paused, as did Petrov, and considered this just a false warning? Drama aside, if the United States and Russia had started a nuclear war, just how many people would have been left to talk about it?

While I admire Lt Col Petrov’s character in saying no, I wish many others throughout history would have displayed his coolness in decision making. Think of the wars that might not have been started, marriages that might not have failed, the bad business decisions and financial ruin that could have been avoided, and the lives spared from the ravages of poor health choices. We all have had times when “no” should have been the first words out of our mouths and yet wasn’t—and how we wish we could turn back the clocks!

Psychologists do fascinating work in studying the biases and motivations that lead us to make the decisions that we do. Naturally, having poor information is always a recipe for disaster, but these experts reveal that we as humans have so many other ticks, cognitive biases, and inclinations that we really can’t use “I didn’t know” as an excuse all that often.

Just think of Confirmation Bias for example—that tendency to interpret new information through a filter so that this new data fits our already established beliefs. Then there is Hindsight Bias in which we examine something and say “I knew it all along!” We must guard against these and many other traps (see this list: Biases) for some can even be dangerous—such as in the case of “I have never had an accident driving home in a snowstorm so why would I this time?”

Many of my friends are surprised when I tell them that a very large chunk of the training that I have undergone as both a military and airline pilot deals with being comfortable in saying no to other crewmembers. Doing so buys time to reevaluate a situation and by throwing a “no, give me a moment” into the discussion slows things down and allows for a differing view.

A Colonel I once served with at the Pentagon had an admirable way of trying to avoid bias problems. At the end of an important decision-making meeting he would randomly choose one of the participants to argue why he shouldn’t take the course of action everyone had just decided upon.

That sounds a bit odd after having done so much planning, information seeking, and consensus building, but it made everyone think as the person he called on had to rapidly formulate an intelligent counter argument.

He liked to recount American military failures (or near failures) and would tell the details of the 1944 U.S. Army attack against Nazi forces in the Hürtgen Forest of Germany or the 1943 allied attack against the Japanese on the island of Tarawa in the Pacific in which soldiers’ lives were basically wasted. “If only someone on the planning staff had simply said “no” a lot of lives would have been saved” he mused as he weighed the consequences of bad decisions. He made good on his talk and was willing to take something back to the drawing board even if it meant a lot of work for himself.

These days, both the military and business world run exercises such as the Red Team versus Blue Team gaming scenarios. Here the teams take opposing sides to tease out pitfalls and to ensure the best decisions are made. It doesn’t work all the time, but it helps and allows team members to at least practice saying no.

Yet for all the benefits of games like the Red Team/Blue Team and the many books and speakers encouraging us to do so, saying no is hard and no matter how confident we are we frequently stumble at just the worst time.