In development it seems that the paradox "the more you know, the more you know you don't know" holds true. (see this simple non-development commentary: http://lennymaysay.wordpress.com/2008/04/22/the-more-you-learn-the-more-you-realize-how-little-you-know/)

If you are a thoughtful, honest person, you will need to accept this fact and learn to deal with it.

Confidence, in the sense implied by the question, is a very personal thing that really has nothing to do with a particular skill set or methodology.

On a more shallow note, the sentiment described in http://www.kalzumeus.com/2011/10/28/dont-call-yourself-a-programmer/ (section: You radically overestimate the average skill of the competition because of the crowd you hang around with) has always helped me.

I would suggest that you learn to be more confident in the work that you have done as opposed to building confidence in your skills as a whole. The single best way to do this is to write repeatable tests for all of your code. It will work wonders on your psyche.

In development it seems that the paradox "the more you know, the more you know you don't know" holds true.

If you are a thoughtful, honest person, you will need to accept this fact and learn to deal with it.

Confidence, in the sense implied by the question, is a very personal thing that really has nothing to do with a particular skill set or methodology.

On a more shallow note, the sentiment described in http://www.kalzumeus.com/2011/10/28/dont-call-yourself-a-programmer/ (section: You radically overestimate the average skill of the competition because of the crowd you hang around with) has always helped me.

I would suggest that you learn to be more confident in the work that you have done as opposed to building confidence in your skills as a whole. The single best way to do this is to write repeatable tests for all of your code. It will work wonders on your psyche.