I am posting this here because I am really interested in the concept of insight ...

Insight from my therapist is feedback about those aspects of myself which are outside of my awareness. Broadly speaking, those aspects of my personality and character are outside of my awareness because I can't experience myself as others do, or because I am operating within my insular field of assumption or incomplete information. For example, my therapist has challenged me about my understanding of concern versus criticism. I had very limited understanding of others expressing concern for me, I almost always heard those comments as patronising criticisms. When she challenged me about my lack of understanding (and this was something which took several months of work), I was able to see that I had missed information about myself and others.

If we don't believe that others can provide insight, I think we are missing interesting and exciting aspects of ourselves and others. Therapists are no better nor worse placed than others to provide that insight.