Do you have a pre-game ritual before big life and career moments? Do you get nervous before a  big presentation? Do you feel the weight of expectation when asked to exit your  comfort zone and take on a project that could either go great and define your career or go wrong and lead to disaster?

Rob O'Neill can probably relate.

O'Neill's gripping book, The Operator, Firing the Shots That Killed Osama Bin Laden and My Years as a SEAL Team Warrior, follows a reliable format--right up to the point where he sorts out that the secret mission he and his  SEAL Team have been tasked with is to raid and kill the most wanted man on earth, Osama Bin Laden.

He executed over 400 combat missions, including the famous Operation Red Wing (Marcus Lutrell's Lone Survivor) and the rescue of Captain Richard Phillips from Somali pirates in the Indian Ocean.Yet it's the raid to kill Osama Bin Laden that he'll be most remembered for. O'Neill fired the three shots that killed the Al Qaeda leader on the third floor of a secretive and well-armed compound in Abbottabad, Pakistan.

About three quarters of the way through The Operator, O'Neill starts to detail his selection for the assault team, the training workup for the raid and the final preparations just prior to embarking on the mission that would change the world. A mission he and his SEAL Team brothers expected to die on.

During the 90-minute helicopter flight in, O'Neill sets the scene:

"We were ninety minutes out from the compound. To keep my mind from spinning off somewhere I didn't need it to go, I started counting. I learned that as a sniper. Counting keeps you cool, keeps your mind engaged, but in idle. I counted zero to a thousand and a thousand to zero. Zero to a thousand and a thousand to zero.

"I must have done that a dozen times before we banked to the south about eighty minutes into the flight. Now we were on our attack run, and as I was counting, just between random numbers, I began to repeat, 'Freedom itself was attacked this morning by a faceless coward, and freedom will be defended.'

"I was thinking, 'Holy shit, this is really it. I'm on this mission and we're going to go kill this son of a bitch.'"

It's a heart-pounding recount of the helicopter ride to history. O'Neill's team would go on to execute the mission. The 30 minutes or more in that compound are alone worth the read of this book.

But it's the pre-mission preparation that perhaps carries the greatest transferrable lesson.

Navy SEAL  training and mission prep are legendary. For this mission, they built an exact replica of the Bin Laden compound in the hills of North Carolina. They roll-played different battle scenarios over and over again. On the real mission, one of the helicopters crashed on site, a potentially fatal disaster, O'Neill simply stated, "We'd planned on that."

Even with all of this preparation, when en route to carry out one of the most significant missions in U.S. military history, O'Neill found calmness in a simple counting cadence: "Counting keeps you cool, keeps your mind engaged, but in idle."

This type of pre-game ritual can do just that for you prior to big events in your life. If not counting, perhaps it's a meal or a pair of socks or a travel routine.

As part of my current gig, I routinely speak in front of hundreds of people. Sometimes these are prepared talks and others are less formal.

No matter the format, I always picture myself as a pitcher in the bullpen waiting to enter the game. It's the calm before the storm.

The performance is all about my preparation, not the moment. I'm never on missions with Rob O'Neill like implications, but the principal remains the same.

Calm your mind. Rely on your preparation. Execute the mission.