Punishment/prison

We all know that we cause our own suffering right? If you hit someone, you feel bad about it. If you kill someone, you’ll be thinking about it until you die. What is the point of prison? Our punishment comes naturally when we break the moral codes. How does caging a man like a beast, make him more of a man?

Im sure I could write ten pages on this, but I’d rather open it up for discussion and hear other people’s input.