You did some things when you were younger that you're not proud of now that you're older. We all have. Sometimes, an apology would open an old wound or make us feel better while making someone else feel worse. If that's the case, it's not worth it. Other times, a sincere apology can make things right.

Once you know better, do better. Some of the stuff I did in my early 20s horrifies me today. I didn't commit any crimes but there were times I pretended to like someone just to sleep with them, I was often selfish, and didn't think of others feelings as much as I should have. But I realized these things and stopped doing them. If there's karma, I think I've balanced mine out with good deeds and volunteer work.

None of us can change the past so ruminating on it is a waste of time. I know this is easy to say--I still ruminate--but I really try to improve myself as I move through life. That starts with forgiving myself for stuff I did when I was a different person.

If it helps, scientifically, every 10 years or so all the cells in your body have been replaced by new ones so, technically, you really ARE a different person.