these days... i have been wondering,why do not have some feelings i should have..

I really dun understand,why i did i care for this world.. It was really none of my bussiness,I dun feel a reason for me to care.Not only for the world,but i remember that i dun use to care for my friends too..When i was primary 6,i find people to whack for nothing.I did get caught,the teacher asked me,"Why did you hit him?"

I replied,"there isn't a reason for me not to hit him."
he asked,"but he didn't even do anything to you and they will get hurt."
I replied,"Why should i care??i isn't me that feels the pain."

Suddenly,he look at me like some kind of animal or something.bring me to the office and talk a lot of crap.Well,i really,really,really dun understand still.I dun feel like i am doing the wrong thing.No shame nothing,they said i should be like feeling something.But what??Now sometimes,my body will just move to protect someone.hoping that... I didn't even know what i was hoping for..Can anyone tell me if this is the right way feel?I dun really know what's right and what's wrong after i met u guys..jasper,arshad,ruby or just anyone else from this school.U people are all so different from my usual friends,so..so friendly.

Can anyone help me??how?why?or what?is the right thing??