There was an episode of 3rd Rock from the Sun in which the aliens puzzle over the discrepancy between what people often say and what they think and feel. At the end of the episode John Lithgow's character has a sort of epiphany in which he realizes that telling "white lies" functions as a sort of social lubricant in which people are often less than truthful in order to preserve relationships that might otherwise be damaged by too much forthrightness. In many cases this kind of pretending is socially sanctioned -as Jackie says for example when people ask you how you are it's generally understood that this is a mere social pleasantry and the appropriate and expected response is brief and direct. My 11th grade high school English teacher illustrated this the point by saying: "Next time someone asks how you are, really tell them!" Everyone laughed, because we could all readily imagine how that would be received.
Contrary to what we have been taught as children honesty sometimes isn't the best policy. As someone who values forthrightness, I can tell you that from experience. When I did my honours oral exam in uni for example the chairperson wrapped things up by saying "If I can give you some advice, when you do these things in the future...". The she paused, weighing her words. "Don't volunteer information?" I suggested. "Exactly!" she said. One of the questions I was asked was about the books that had influenced me the most in the course of my studies. One of the ones I mentioned was Paul Kennedy's "The Rise and Fall of the Great Powers", which happened to be true, but I did so knowing full well that one of my professors sitting right there was quite vocal in his disapproval of the book. Was that the smart -as opposed to the honest- thing to do? Probably not, both from the standpoint of my grade on the exam and my prospects for graduate school (had I chosen to pursue that course). In that particular instance I don't think my prof was unduly put off, in fact I flatter myself that he was quite impressed with my -uh...candidness (he'd had plenty of exposure to it during his seminar on war and society in the 20th century!) That makes him the exception though. As the chairperson's gratuitous advice illustrates, when you want to impress people (not just professors but potential employers, mates, etc.) its more profitable to tell people what you think they want to hear, even if it's not the truth. If anything the expectation that you SHOULD bend over backwards to impress someone renders your failure do so doubly disappointing.
We all say we value honesty, but the truth is in many social situations hypocrisy will get you much further much faster!