What makes effective leaders?
People that strategically channel their ego in a way that serves them better; that have learned to use their ego as fuel for REAL success.
REAL success is the one based on a solid foundation that will CONSISTENLY stand up to any storm! Even if we fail, we still believe in ourselves and our dreams, and we keep moving straight and forward.
I am not in agreement with the artist's opinion below, that we should not believe in our greatness.
That's not the problem. Of course we MUST believe in our greatness, but we MANAGE the ego. 
Think Navy Seals. They know they are the best, right? And yet, they remain humble. Why? Because they place a high value on staying alive and achieving their mission. They embrace remaining humble so that they remain open to learning, adjusting, and growing. For riders, this means being open so we are able to receive valuable feedback from our horses and the environment (this is the staying alive and achieving your mission part!)
Some riders struggle to step into becoming and owning the fact that they are Equestrian Rockstars. Even when all the credible evidence is there (after years of hard work and wins), they still shy away from the limilight and promoting themselves. (Is it promoting yourself in a negative way or inspiring others and building your business?)
Other riders, especially when they start having progress or racking up the wins, are easily unseated with cockiness and arrogance. Arrogance is a belief and attitude that we know it all already, so not only are we not open to learning, we're SO amazing, we don't even have to apply ourselves or even fight that hard anymore!
Our strength does not come from knowing we are strong. Our strength comes from the reality check that we are both strong AND imperfect human beings (vulnerable!). The top of one mountain is the bottom of the next! We are great only IF we apply our greatness while rocking the skill of mitigating our weaknesses. Or as my husband loved to say, "Pray, but move your feet!"

(Sidebar: "Move your feet" is the part where we acknowledge we are STILL human!)
And what about the riders that are in the process of achieving wins in the near future, who are working hard but still struggling? If they can't become humble, and then reframe and embrace the journey of the comeback trail, they will quit their dreams altogether or back down permanently to a level where they CAN win because their ego can't tolerate what they perceive as losing or even ever looking bad.
These are all examples of toxic ego with the exception of the Navy Seals who execute their missions with what I call the "collected ego". The collected ego is driven by the positive force of believing in your greatness, but it is then strategically managed by placing a higher value on humility and embracing the learning opportunity and growth from uncertainty that ONLY comes from staying laser focused on executing every stride; while remaining aware and calculating the valuable feedback from our environment and adjusting with the right timing.
All that requires effort to consistently work on and apply the right mental skills and channeling our inner warrior so we will fight for the outcome. 
One tactic outperforms the others, can you guess which one that is? 
Below is the article that I referenced above on believing in our greatness. 

25 Ways to Kills the Toxic Ego

"In a New York minute, everything can change." The Eagles

Are you a control freak?

Learn how to rein in and control the toxic ego! 

It takes consistent practice, but the rewards are lifechanging! 

Wishing you all the strength, vulnerability, and adjustability to make a decision to ...

Apply the effort ... 

To creatively engage in a new, winning approach to riding and your life!

Nancy Dye 
Breakthrough, Equestrian Peak Performance Mental Skills Coach
Emotional Strength & Resiliency Trainer
Strategic Interventionist

Nancy Dye
Elite Lifestyle Transformations, LLC
11924 Forest Hill Blvd., Ste 10A-211
Wellington, Florida 33414
United States of America