Is ignorance bliss or would you rather know something that will surely make you miserable?

Just curious to read what anybody has to say about this general issue. It seems that on the surface, one would not want to be lied to; on the other hand, some people feel that white lies are necessary in order to relate to one another. Similarly, what do think about "lies of omission." Would somebody be lying if they neglected to divulge an important piece of information that would drastically change your perception of the situation? Thanks...