Have you ever wondered why sometimes we continue to believe that a guru is pure or infallible, even when we see clear signs that he makes mistakes? This is directly related to cognitive bias such as the sink cost bias and the confirmation bias. On the one hand, the sink cost bias can make us continue defending a guru because we have already invested a lot of time, faith or resources in his teaching. It is difficult for us to accept that that investment does not guarantee that everything he does is right, and we prefer to move forward than to admit that we might be wrong. On the other hand, the confirmation bias makes us look for only the evidence that confirms our belief in the purity of the guru, ignoring or justifying any evidence of his failures. So, although we see questionable behaviors, we tend to minimize them or seek explan