Simon Sinek has written five books, delivered a popular TED Talk, and is one of the world's top speakers on motivation and leadership. In short, the guy meets just about anyone's definition of super successful. 

But that hasn't inoculated him against envy. Even those at the very top of their game torture themselves with jealousy of other's success, he reveals in a excerpt from his new book The Infinite Game, which was recently published on the TED Ideas blog

Sick with envy for the star Wharton professor 

"Whenever I heard the name Adam Grant, it made me uncomfortable. If I heard someone sing his praises, a wave of envy washed over me," Sinek writes. 

"Although there are many others who do similar work, for some reason I was obsessed with him. I wanted to outdo him. I'd regularly check the online rankings to see how my books were selling and compare them with his. Not anyone else's rankings -- just his. If mine were ranked higher, I would smile a gloaty smile and feel superior. If his were higher, I would scowl and feel annoyed," he goes on.  

We might be ashamed to admit it, but these feelings are something most professionals can relate to. But if Sinek's envy is completely common, his response to it wasn't. In the book he goes on to explain how a chance encounter with Grant helped him rethink his relationship to his nemesis and turn his rivalry with Grant into one of the greatest drivers of his success. 

Why every professional needs a "worthy rival."

Sinek goes on to share the story about how he and Grant were slated to introduce each other at an event. 

"I went first. I looked at Adam, looked at the audience, and said, 'You make me unbelievably insecure because all of your strengths are all my weaknesses. You can do so well the things that I really struggle to do.' The audience laughed," he recalls. "Adam looked at me and responded, 'The insecurity is mutual.'" 

It was a funny (and ballsy) introduction, but Sinek's self-revelatory joke ended up being more than a clever applause line. By facing his insecurity head on, Sinek realized why Grant bothered him so much: His fellow author was great at things Sinek struggled with. 

That's a common dynamic, according to experts. We're often most irked by people who highlight our own weaknesses. If you hate arrogant people, it's often because you have unresolved issues about self-confidence. If bragging sets you off, chances are excellent you struggle with tooting your own horn. 

By recognizing what it was his own weaknesses that was triggering his envy of Grant, Sinek was able to focus his energy not on fruitless competition but instead on self-improvement. And that eventually drove him to even greater success.

That's often what a great work rival paired with a little self-awareness can do for you. 

"A Worthy Rival can push us in a way that few others can -- not even our coaches, mentors or advisors," he contends. "Traditional competition forces us to take on an attitude of winning; a Worthy Rival inspires us to take on an attitude of improvement. The former focuses our attention on the outcome; the latter focuses our attention on process."

"It is the focus on process and constant improvement that reveals new skills and boosts resilience. An excessive focus on beating our competition not only gets exhausting over time, it can actually stifle innovation," Sinek insists. 

So forget about winning the competition and vanquishing your work nemesis once and for all. The comparison game is a never-ending soul suck. If you really want to be successful, you don't want your biggest competition to go away. You always want to have a worthy rival. As Grant did for Sinek, the person who makes you sick with envy at first can end up being one of your biggest sources of self-improvement.