In Buddhism they have what is called the Five Precepts. It's a little similar to the Ten Commandments. Yet it's not so much of a "Thou shall not" sort of thing, rather it's a training rule. They are training guidelines, to train, to train for benefits, which I will mention in a minute after I explain them.
The Five Precepts are:
1. To not intentionally kill any living being.
2. To not intentionally steal.
3. To not intentionally speak wrong speech, such as lying and deceptive speech, harsh speech, etc.
4. To not to have sexual misconduct.
5. And to not take intoxicants which confuse the mind.
They are training guidelines which can help us in our practice. For many of you, if you are like me as a typical American, you stole something somewhere along the line. You lied to somebody about something. You probably killed ants, mosquitoes, flies, whatever, and basically as kids do, they are interfering with these precepts all the time. But in general it is because of peer group pressure. My friends taught me how to steal candies at the store, I was told to kill flies in the house. My friends lied, so I lied and so on. Then as you get to be seventeen, eighteen, your friends say, let's have a beer and that sort of thing.
So as kids it is not so much of a direct intention to do it on one's own, it's usually peer group pressure, something that's been done by our friends and so on. However, as an adult we now have a chance not to do it intentionally, to actually stop some of these negative things and the importance of doing them, of course, is to purify ourselves and to have less regret.
When I first started my meditation practice I had regret for the unwise things I did in the past. Now after many years, doing lots of Compassion and Lovingkindness, doing lots of forgiveness as well, understanding conditioning and everything else, I don't have that regret any more, it's gone.
But the regret is also gone because for 20, 30 years I haven't done these things at all. I look at myself now and I am a person who can say that I have never had alcohol in my whole life. I have never stolen anything in my whole life. I have never lied to people in my life. In my life that I have now. Who I was in a past life when I was fifteen, eighteen, whatever, that's a different person. I am identifying with who I am now. I am not a person who steals and so on.
So this is how regret can go away, because we look at who we are now. If we are holding on to these precepts or other good, compassionate guidelines, if we hold to them for one week, we can say "Yeah, one week I did it!" We hold to them for one month, we go, "Yeah, one month I've done it!" One year, ten years, "Ten years I haven't done that, this is wonderful, I am a new person!" So it gives joy and energy, as well as less regret and self-hatred.