Humans tend to blame mistakes on external events, circumstances and people. Admitting failure goes against our ego, as we think it exposes our incompetence, leading to potential loss of respect and self-esteem. 

Recognizing that failure is healthy and a normal consequence of working in a complex environment can help us look at failure as a learning process instead of dreading it. It also helps to let your failure(s) be out in the open, making them visible to yourself and others.