This post originally appeared on my LinkedIn profile December 22, 2014

Don’t worry; this is not a post where I try to convince you that I’ve found the secret formula to sales. Far from it actually. I have always approached sales like a student, in a constant state of evaluation and education. I think a lot of us get discouraged about things that are completely out of our control. However, we fail to recognize the one area of our lives and careers that we have total control over – our emotions.

I relocated a few months ago and am still unpacking boxes. I recently came across a book, The Greatest Salesman in the World, by Og Mandino. Hands down, this is my favorite book written on the subject of sales and ranks very highly with my favorite books of any genre. My copy is nearly destroyed. Dog-eared and tattered, filled with underlines, highlights and notes. I received the copy in 1998 at the end of my freshman year in college.

I was embarking on my first job in sales – a summer “internship” with the Southwestern Company. If you’re not familiar, here is your crash course. I drove from Ohio to Nashville, TN in a caravan with about 15 other students for a weeklong sales training with other kids from all over the country. Then we were given a territory; mine was West Memphis, AR. I knocked on doors that weekend to find a room for rent and then I opened my business as a student dealer, selling books door-to-door. I was essentially broke, homeless and isolated from friends and family. This was a situation where I certainly needed to control my emotions.

I learned some of my best life lessons that summer. Nothing builds character quite like having your teeth kicked in over and over again for 8-10 hours a day, in person, at someone’s front door. After one especially taxing day, I was picked up by the police in front of an apartment building. Apparently one of the residents was not amused when I slyly told her I thought the “No Soliciting” sign instead said “No Smoking.”

Throughout the good and bad days in West Memphis, I kept that book with me. I would read a couple passages each morning. I would read a few while I ate my lunch (usually warm PB&J and water on the sidewalk). I would read after making a sale and after getting rejected. This is a practice I’ve continued throughout my entire sales career. Sure, I’ve read other books, lots of them, but I always come back to Og’s wisdom.

If I become overconfident I will recall my failures. If I overindulge I will think of past hungers. If I feel complacency I will remember my competition. If I enjoy moments of greatness I will remember moments of shame. If I feel all-powerful, I will try to stop the wind. If I attain great wealth I will remember one unfed mouth. If I become overly proud I will remember a moment of weakness. If I feel my skill is unmatched I will look at the stars. Today, I will be master of my emotions.

Are you always in control of your emotions? Ever let one bad call or meeting dictate the rest of your day? Have you lost a customer and allowed that defeat to ruin the rest of your week? Or did you crush your goal and then try to rest on your laurels? All of these reactions ultimately waste time and as we all know, time is a non-renewable asset.

Weak is he who permits his thoughts to control his actions; strong is he who forces his actions to control his thoughts.

All Quotations from The Greatest Salesman in the World, Og Mandino, 1968, Bantam Books.