I just read the VerySpatial post linking to Builder.com Ten Commandments of Egoless Programming via TheSteve0. VerySpatial likes Commandment #3: No matter how much “karate” you know, someone else will always know more.
I like this one too, but for very different reasons. This rule, to me, is a signpost showing where ego can be put to use: disruptive technologies. In essence, if no matter how good you are, someone will always be better: then change the game.
My other favorite?: The only constant in the world is change. Keep your ego. Lead.