Matt gets all contemplative and nostalgic again, by looking back over his journey from arrogant Web Designer to enlightened UX Designer. He posts that there are four pillars of UX mastery.
As Matthew Magain says, it may be obvious to some practioners, but it's worth pointing at these 4 pillars that are Theory, Practice, Tools and Mentor. A good UXer should find the right balance between those 4 pillars (which is the tricky part!).
Source: Matthew Magain, UX Mastery