I think for most people, it is a familiar feeling. That sudden realisation that you have forgotten something that you shouldn't have: A birthday, an anniversary, your partner's name.
On Friday night as I was reading the paper, it hit me. I was disappointed in myself; frustrated with my failings. It was Valentine's Day the next day and I had forgotten to buy a present.
It wasn't for want of opportunity.
That very day I had wandered around the shops aimlessly for a solid hour. But instead of searching for chocolates or roses I had purchased 10 plastic coat hangers and an electric toothbrush. These were not items that fancy wrapping paper could convert into gifts.
When I tired of berating myself, I shifted the blame to Valentine's Day instead. I am pretty good at forgetting dates I regard as important, let alone those I am indifferent to.
The fact is, I think we should all forget it.
If you're single it makes you feel like you're missing out on something. You might even agree to go to a depressing singles' party.
If you're in a relationship it is just another date to remember and present to worry about.
Personally I would prefer to make such gestures out of choice, rather than obligation. On Valentine's Day they feel commercially contrived and cheesy.
Despite these sentiments, I am old enough to understand that fighting against the system is rarely a wise move in such situations. Better to just buy the gift, make the most of the day and complain about it later.
Even so, I did not expect to have the opportunity to complain about it on Valentine's Day itself.
I had travelled over 20,000km to be with my girlfriend. I thought on Valentine's Day I would be otherwise occupied - no doubt giving someone else the opportunity to complain about something (I mean the present - or lack thereof).
But as I sat, alone, writing this blog, February 14 in Finland seemed very similar to Valentine's Day in New Zealand.
It wasn't that I was in trouble because I forgot to buy a present.
In fact, I wasn't in trouble at all. For in Finland, February 14 is not called Valentine's Day but Friend's Day, and as the name implies, it is more about celebrating friendship than romance.
Although some Finns treat it as a romantic occasion, the majority who recognise it see it as a chance to make contact with old friends, either by catching up for a drink or sending a card.
Sanna was having lunch with her old friends from school. I was abandoned, with only pizza and DVDs to keep me company.
It was quality time spent with my old pals Al Pacino, Robert DeNiro and pepperoni. Friend's Day was great.
"How did this Friend's Day come about?" I asked Sanna when she came home, having fruitlessly searching the internet for a decent explanation in English.
Sanna didn't know either, and even amongst Finnish language web pages, information is scarce.
Until relatively recently there was nothing like Valentine's Day in Finland.
Over the course of the 1980s interest in what other countries were doing on February 14 developed until in 1987 "Ystävänpäivä" (Friend's Day) was officially added to the calendar.
Of course, there is nothing unusual about the importation and adaptation of foreign customs into a culture. One of the most interesting aspects of travelling is not just discovering new cultural traditions, but seeing how familiar customs are altered to suit local conditions.
An example is the way Christianity has been altered in the village of San Juan Chamula in southern Mexico.
The indigenous Americans of this village believe that Coca-Cola is divine, drinking it while praying to an altar stacked with empty Coke bottles and other more traditional Christian icons.
Burping is considered to be the cleansing release of evil spirits. Talk about a marketing coup.
But what is peculiar about the adaptation of Valentine's Day to Finnish culture was that it occurred so recently.
Finland is not isolated, poor and illiterate San Juan Chamula.
People in Finland in the 1980s were aware of how most of the world celebrated February 14, they just decided to change it.
This adaptation might be a reflection of the Finnish culture.
It seems that the Post Office was a driving force behind the adoption of Friend's Day - after Christmas it is now the most popular time to send cards - but decided that Finns were too shy to go for Valentine's Day as we know it.
Whatever the reason, to me there is something very sensibly Scandinavian about all this. Why import an annoying tradition, when you can make up your own?
People in relationships welcome the opportunity to spend some time with friends, and those who are single don't feel like they are deficient.
It's innovation like this that makes Finland great.
In what other country in the world would your girlfriend be genuinely surprised and happy with an unwrapped gift of 10 coat hangers and an electric toothbrush?
I say forget Valentine's Day - at least your friends won't get angry.
- Matt Kennedy-Good
Pictured above: Sanna's little cousins celebrating Friend's Day. Photo / Matt Kennedy-Good