They were damaged in childhood and turned off all feelings and never developed empathy.
OR they may have a condition that causes behavior that looks insensitive; eg: Asperger's Syndrome, whereby they can not read social cues and do not naturally respond the way "practiced" people do.
OR they were raised by emotionally incestuous narcissists and have no personality or soul; do not love themselves (for they have no self) and cannot love or care about others at all. There is no ability to put oneself in another's shoes but they are good actors. They have two feelings: superiority and contempt.
i agree mostly with this reply as it covers lots although i would add frustration/anger and self blame to the feelings.
If we can't relate to something or we are ignorant about it, it's kind of difficult to know how what might cause offense. Experience is the greatest teacher I guess.
life,media,hurts and pain can numb the heart and callous people to the feelings and emotions of others...
Because they do not sense! Or.. they do not have their senses.
Hard Hearts, or ignorant hearts, sometimes are one in the same
They are focused on themselves. Cant see/feel other ppl pain.
They're not conscious.