We all have an opinion but sometimes we do not have a choice to give it.
For example, my wife is in a shop trying on a new dress (yes, sometimes I do treat her) and asks me if her butt looks big in it. No matter what I may be thinking (often about hobbies, will my team win the next game, what to eat, why is there no seating and magazines for men in female shops) I do not really have a choice to express exactly what my opinion is on the said dress because a married man just needs to answer with what his wife wants to hear to her rhetorical question. So saying "no, honey, you look great" and withholding my opinion means the shopping trip is a success and I get home on time to watch the game on TV.
