learning the truth about the world, is important in journey towards enlightenment, but is painful at time when we learn the horrible truth of reality...
for example the holocaust, extreme poverty, the sex slave trade, and so on.
there is a certain comfort that is shadow of blissful ignorance and that gets shattered upon learning the truth, and then you have to live with that sadness and there is no going back, no un-learning the truth, in the end, it is all worth it, it is all part of the enlightenment experience.
10/15/12 update
learning the truth,
dont take half measures,
take full measures.