Empathy is: I recognize how you feel or what you need.
The Harvard Gazette wrote an article about Gyalwang Karmapa - leader of the 900 year old school Karma Kagyu school of Tibetan Buddhism. In it Karmapa states, "The most dangerous thing in the world is apathy." "..causing people to have no help when they need help, no friends when they need friends. We think of weapons, violence, warfare, disease as terrible dangers, and indeed they are, but we can take measures to avoid the them. But once our apathy takes hold of us we can no longer avoid it. "
The easiest things to do when we get overwhelmed is to say things like: "screw it"; "I don't care"; "that's their problem"; "I don't have time for this". Then disappear out of the situation as though your apathy won't affect you in the future like it is affecting those around you now.
Society had conditioned you to be apathetic. So you won't question when you see something wrong going on. From youth we are taught to be complacent. We shake our heads and say "that's too bad" when something bad happens or blame someone else for it happening. But then put it out of sight - out of mind. Apathy can spread like a disease. Infecting your life and those around you. Not caring is the easy thing to do - effortless even. Because effort requires involvement.
Apathy is someone looking at you offering a hand in friendship and you pretending not to notice it - looking away rudely. This causes you to be alone as well, not just them. It's safer to be numb than it is to care. But it is also isolating and lonely. You can fill that void with shallow amusement, rationalizing, but in the end never really feel happy.
In "The Long Tomorrow" author Leigh Brackett writes, "There has never been an act done since the beginning, from a kid stealing candy to a dictator committing genocide, that the person doing it didn't think he was fully justified. That's a mental trick called rationalizing, and it's done the human race more harm than anything else you can name.
Another author, Ayn Rand, writes " Rationalization is a process of not perceiving reality, but attempting to make reality fit one's emotions."