VALENTINE’S DAY 2008 — You’d think I’d have been drooling over some dude, or at least stuffing my face with candy.

Instead, I was basking in the cold glow of a laptop and an e-mail that sealed the fate of a friendship that had been in limbo since day one.

Three and a half years. Certainly not the longest or oldest of my friendships, but an important one, nonetheless.

Friendships can end for a variety of reasons — sometimes it’s over a guy, a betrayal or the result of malicious gossip.

I̢۪ve experienced a couple of those, witnessed quite a few, and things can get ugly fast, like a messy breakup.

Sometimes there are nasty exchanges or dead silence, as both parties retreat to nurse wounds and load up on verbal ammunition.

But then there are friendships, like relationships, that die ever so slowly, where numerous attempts are made to come to terms with and work through problems that have no solution.

The effects of a demise like this are never apparent right off the bat. All I was feeling Feb. 14 was overwhelming relief.

I could move on at last.

But several weeks later there was love drama on the horizon, so of course I reached for the phone. I was halfway through dialing her number when it hit me.

I was the one who̢۪d put the final nail in the coffin.

Regret replaced relief.

I wondered if I̢۪d been a smidge too impulsive axing three and a half years of friendship with one icy e-mail.

I hung up the phone.

“Boyfriends come and go, but girlfriends are forever.â€Â Or so they say.

This must be why it hurts so much when it doesn̢۪t work out.

A good friend is a confidante, shrink and surrogate sister all rolled into one, but sometimes personalities just aren̢۪t compatible.

In the weeks that followed, the drama died down and I started seeing someone new.

So I called one of my other friends instead, then deleted her number, finally.

When I really think about it, I would not have done anything differently even if I could have. When the bad times begin to outnumber the good, and every conversation morphs into an argument in a matter of minutes, it̢۪s time to move on.

And there̢۪s no sense in holding on to regret either, because you can never go back and do things over.

It̢۪s called the past for a reason.