This is the last part of the HBR article and it's a great point - be passionately curious. This trait reminds me of many people I know who are successful and well liked because they are humble and willing to do for others. Often when I read about nationally known entrepreneurs they are described as curious. Their brains are always in search of answers, new thoughts and new ideas.
Einstein said of himself, "I have no special talent, I am only passionately curious." This quote from HRB shows why this trait is important to both success and humility. When you and I are curious we are admitting we don't know everything and that shows when we treat others as sources of potentially good ideas instead of just gears in a machine. When others realize that we see them as important and meaningful to the organization and to the overall success, they are motivated to give more and be more curious themselves. The result is a solid team and good success.
To be humble isn't just good for you and me, it's good for everyone around us and it is good for all of our success. Besides it being the right thing to do, it's just a more enjoyable way to live.