If I have learned anything, the hard way, it is that being right in one's own mind isn't the same as being right. Humility is an interesting thing. It doesn't mean being a doormat. It certainly isn't denying or not standing up for truth, but it generally does mean applying the concept of "a gentle answer turns away wrath."
Now, when I consider trying to lead something towards positive change, change towards truth, I generally try to avoid the top spot. There can be value in that kind of control, don't get me wrong, but I find that if I am forced to influence, forced to create a business case, forced to prove truth rather than declare it to be so, I am also forced to speak softly. I am required by circumstance to put energy into actually knowing what I am talking about instead of relying on a positional strength to force my way. And at the end of the day, you learn through all of this research to prove "your truth" that you knew less before the process started than after, and it keeps you humble, and keeps you learning, and best of all, generally keeps things moving towards a better future!