I doubt that anyone gets through life without picking up some regrets along the way.

In fact, I doubt that many people get through life without picking up some major regrets along the way.

We can all look back on things we wish we had done differently.

We can all look back and think, if only.

Every decision we make brings with it the possibility of regret, because every decision we make closes as many doors as it opens.

The Danish philosopher Soren Kierkegaard (1813-1855) expressed it beautifully: "I see it all perfectly; there are two possible situations - one can either do this or that.

"My honest opinion and my friendly advice is this: do it or do not do it - you will regret both."

HANDLING REGRET

Regret can be defined as an unpleasant emotional reaction to a past event where we feel that if only we had chosen or acted differently, things would have turned out better - for ourselves or for the people we love.

When it comes to handling regret, there are two schools of thought.

Some people claim that regret is a useless emotion.

You can't change the past,? they say. What's done is done. So why torture yourself about it? Move on!

The thought here is neatly captured by the English proverb "It's no use crying over spilt milk."

There is a lot of truth in that.

There really is no point getting upset about things that have already happened and cannot be changed.

Sitting and brooding over past mistakes and missed opportunities achieves nothing, and can lead to depression.

Others claim that regret, properly channelled, can be a healthy and even a positive emotion.

Those who adopt this view point out that regret can be instructive.

It cannot change the past, but it can illuminate the present.

There is a lot of truth in that too.

The Spanish-born American writer George Santayana (1863-1952) once said: "Those who cannot remember the past are condemned to repeat it."

Similarly, those who refuse to reflect upon their past mistakes lose their best opportunity to build a better future.

LEARNING FROM MISTAKES

I think that there is something to be said for both viewpoints.

Sometimes, you have to stop wasting your time and energy brooding over the past.

But at other times, you have to face up to the mistakes you have made and accept responsibility for them.

Regret, when it is inward-looking and stuck in the past, is a useless and damaging emotion.

But it need not be that way.

The Buddhist monk, writer and teacher Thich Nhat Hanh - whom I have mentioned in my previous column - gives what I think is some very wise advice on the subject of regret.

He points out that very often we make mistakes not because we wish to harm anyone else, but because we are "unskilful".

We act wrongly through ignorance, foolishness or fear.

We make bad decisions because we lack the wisdom and experience to make good ones.

"As we are human beings, we make mistakes," he said.

"We cause others to suffer. We hurt our loved ones and we feel regret. But without making mistakes there is no way to learn."?

And that is really the crux of the matter. Without making mistakes there is no way to learn.

If we remember this, we can feel regret for what is past, but remain hopeful for the future.

As Nhat Hanh put it: "If you can learn from your mistakes, then you have already transformed garbage into flowers."

•Gary Hayden is a philosophy and science writer.