Why is Crime a crime? What makes Normal normal?

When did human begin? Who actually can give a exact year and date without going back in time?
What makes you think that "Killing" is crime? And what makes you think that "Stealing is rediculous?
You might not think so if you are a thief or murderer, and I am not here to comment for you, neither supporting or against.
I mean, many "Heros" we think of do kill others, such as Iron Man and Bat Man."They are just killing the Bad Guys",Right?
What makes you think that killing bad guys is right thing to do? What makes it become a Normal in your mind?
"Oh man, those are just in the films, not in real", Yes, but how about the ones who do execution. Are they doing the right thing?
When we are kids, things go into our mind, without filtering, straight in to deep in our brain.
But we were just told by the adults, what makes them right? Maybe they are just one of us.
Smoking and acohol would have been banned if we discovered them earlier, because they are one of the drugs.
They haven't, Why? Because human have used them for such a long period of time, which have become Normal for us.
How about killing? How about raping? How about robbing?

What is normal?
We have to go to school, from nursery , to primary school, and upper school, and lastly university.
Life then start from there? Or going to be ended at there?
Within these years, we have to be normal, and to follow the Rules, which was created by human.

So, What are we?
What are rules?