On the O'Reilly Software Engineering blog there's a post from Gregory Brown sharing what he thinks is the definition of a "proficient programmer" and how it differs from competence.

Do you know what the difference between competence and proficiency is? That sounds like a trick question, because the words seem to mean the same thing. But the subtle distinction between them is critically important.

Competence means having enough experience and knowledge to get stuff done; proficiency involves knowing why you are doing something in a certain way, and how it fits into the big picture. In other words, a proficient practitioner is always a competent practitioner, but the opposite may not be true.

He goes on to talk about the Dreyfus Model of Skill Acquisition and how it relates to the biggest bottleneck he sees for developers: "crossing the divide from competence to proficiency." He defines what it means to be a "competent" programmer first and then one of the things junior developers struggle with - thinking knowledge is enough to make you more competent. He gives a more concrete example of this with the use of the Memento pattern, when to use and - for the competent side - when it breaks down.

He ends the post with some suggestions that can help you if you're wanting to make the jump from "proficient" to "competent" (even if you've been programming for a long time, some good tips here).