Why can't people accept that they may have something to learn?

I had a client who use to ignore everything anyone suggested unless it was something he already wanted to do. On one particular issue, where he had no experience at all, he had a very locked in point of view. I had tried to convince him to think differently, as had others. Then one day, after someone else tried to convince him, but failed, he turned to me and said,"everyone keeps on saying the same thing. I am looking for someone who will tell me that I am right." So, he saw the fact that everyone kept on telling him that he was wrong as evidence that no one but him had the right answer!