There are immense costs of doing wrong, not only to society, but to the preparatory. Look at the lives of most people who rejects ethics and discipline, and the chaos and misery that so often follows. This punishment is almost always worse than whatever society meets out.
The greatest portion of peace of mind is doing nothing wrong. Those who lack self control live disoriented and distributed lives.
Consider the fugitive who willingly turns themselves in after years on the run. Why should they do that? They were free, one step ahead of the law, but they gave up! Because the guilt and stress of the fugitive life eventually gets worse than the prospect of lost freedom in fact, it was its own kind of prison.
It’s the same reason why, as child, you might have confessed lie to completely unsuspecting parents. It’s the reason why one partner might voluntarily admit to a crushing infidelity – even though the other partner had no idea. “Why are you telling me this?!” the betrayed shouts as she walks out the door. “Because things have been going so well and I couldn’t take it any more!”
That is why so many petty criminals confess or voluntarily surrender. They don’t always stick to it, but at the lowest moment, they finally realize, this is no way to live. They want the peace of mind that comes with doing right. And so do you.