Talking from my experience in putting together several development shops, I can assure you that even with very high standards of initial resume scanning and phone screenings, the vast majority of the programmers I have interviewed, came up light in skills, talent and knowledge.
More than this, if developing software was not such an extremely difficult process, this would had been directly reflected on the related pay rates, that are way more than the average, given the same level of typical skills, like educational level and years of experience.
As I said before, becoming an accomplished programmer, requires years of formal eduction, eternal reading and experimenting with new technologies, tons of real world professional experience and more than anything else talent.
An interesting related article from the top Computer Scientist and AI guru Peter Norvig can be found here:
Teach Yourself Programming in Ten Years
http://norvig.com/21-days.html
