In one case, Hiring within versus outsiders, Nepotism, and sheer volume of people applying versus positions available. I could fine-tune the answers to stock interview questions. I'm really bad at "Tell us about a time when..." because my actual job doesn't provide all that much drama or excitement. I have no sexy stories. In the other cases, it's usually just being 42 and no background in what I applied for. Other people have background relevant.