Interviews are like standardized tests. Just because one doesn't do well on them doesn't mean that person is unintelligent or wrong for the job. Many of the managers doing the interviews are in those positions because they were not well liked or very good at flying the line in the first place. In that regard, you could take your rejections as a backhanded compliment. Like Jeremy Lin, don't stop believing in yourself just because you have been kicked back a couple times.