Why we're alone?

I always wonder what makes people feel lonely?What makes them stay alone?If it's destiny,I can't agree.I can't think that human is so humble against it that can not even find a friend,or escape of the black and humid prison of lonliness.Destiny is not such a bad enemy to make you people stay alone else?The person,it self?No,far from it.Every one is looking for a friend,or atleast something to share the feelings with.No one never ever choose to be isolated what is it?I can't think of anything more don't know,I myself prefer to be alone than staying with someone whom I can't stand.
but as I believe there is a great power left left within human to overcome the obstacles,then why they can't throw away loneliness?How is the way of defeating it?Which way is true?What's the true way?I don't know,and who dares to say that he/she knows?I belive it's everyone's question questioning is not enough,we need to find an answer.