In Chapter 24 ("Enjoy Humility") of the little book Just One Thing, author Rick Hanson explains:

The root of the word "humble," comes from the Latin for "ground." With humility, you abide like the earth itself: solid, unpretentious, creating value without fanfare.

...

Humility embodies wisdom. It recognizes that everyone, including the grandest, is humbled by needing to depend on a vast web—of people, technology, culture, nature, sunlight, and biochemistry—to live a single day. Fame is soon forgotten. At the end of it all, we're each reduced to dust. Humility helps you be at peace with these facts.

^z - 2013-03-28