I don't know everything, so I sometimes have to rely on other people (partly sarcastic, 100% true).  One thing I keep running into at work is when I ask someone a question and get back a thoughtful, well-stated non-answer.  It has a bunch of words, and it's internally self-consistent, and it has the appearance of an answer, but it's completely devoid of content.  And not because they didn't understand the question or I didn't understand the answer.  There's simply an unwillingness to actually provide a concrete answer.  It could be that they don't want to take a stance on something, or they don't want to overstep their bounds.  Or sometimes it's that they don't want to say something wrong and suffer any consequences.  I don't know if this is because I work in engineering, where the men are sometimes ... unsure of themselves, or because I work in the government, where the people are often ... unsure of themselves, but there's a definite issue of people saying a lot of words and providing literally zero content. 

Related:  But-heads