Early on, we talked about the importance of not holding a grudge. Regret is closely related to that concept, but its directed inward rather than toward others, and its more a feeling of sadness than anger. I think of it as a form of guilt.

You wish you had done a certain thing that you never did, or that you had not done something that you did. You keep reliving a certain moment of action or decision, wishing you had acted differently.

Heres an example. In my business, I manage investments for clients. By the time they find their way to my office, theyre usually over sixty and have been investing for quite some time. That being the case, they of course have an existing portfolio of investments.

A discussion with one new clientwell call him Jakerevealed that he had sold a particular stock years ago that, had he held on to it, would have made him a multimillionaire. To compound his woes, he had used the proceeds from that sale to buy shares in a company that quickly lost a great deal of its value.

As you might imagine, Jake constantly tortured himself over this event. I cant believe how stupid I was, he would say. Why didnt I just hang on to that stock? Every time we talked, this sentiment would work its way in to the conversation.

What a waste of time, emotion, and mental energy. He was so preoccupied by these events that he couldnt bring himself to make a decision nowhe was afraid of repeating what he had come to view as a tragedy.

Eventually I was able to convince him that he had simply made the best decisions he could with the information he had available at the time; thats all any of us can do. Maybe it works out, maybe it doesnt, but weve done our best. Thats all you can expect.

No amount of thinking about it is going to change what happened in the past. Your life lies in the futureand thats a good thing, because you have the ability to influence the future. You can do nothing about the past. Leave it behind you. Youll make plenty of mistakes in your lifetime, but dont concern yourself with them. Walk boldly ahead.

Excerpted from The Graduates Book of Practical Wisdom: 99 Lessons They Cant Teach in School by C. Andrew Millard, published by Morgan James Publishing, available in bookstores and online. &opy; 2008 by C. Andrew Millard; all rights reserved. For more information visit www.wisegraduate.com.