1.   He asked me if I knew anything about ley lines and I confessed my ignorance.

2.   But in a recent interview one of the highest-ranking officials of the CIA confessed complete ignorance of the subject.

3.   Far from confessing an ignorance of Japanese culture, the coach offers his own diagnosis for what ails Japan.

4.   I confess ignorance.

5.   Science must confess its ignorance and prepare to be surprised.