This is true, and it's the same in all walks of life. My homie has that MJ mentality of always putting forth his best effort, and he surpassed me because of it.
I got to my ship as an E-4 when he was an E-3. 12 months later, and I'm still an E-4, yet he's an E-5. Cuz is literally one of my supervisors

.
What's funny is that he'd tell you himself that he's not the smartest, or the most clever, or even the most friendly guy, but his work ethic is so much higher than everyone else's, that you can't help but to promote him. He always gets the job done, and he does it quickly and efficiently.
Usually, it'd take an E-1 3-4 years to make E-5, but cuz got that shyt in 1½ years.
Having a high work ethic can take an average guy to some great places.