A friend recently remarked on Facebook that the interns at her workplace had no idea how to write on an envelope, having never posted one in their lives.

I was taken aback - don't they teach pupils these things in school anymore? Then I remembered how, for a long time, I hadn't the faintest clue what the handwriting of one of my closest friends at university looked like.

Aside from nostalgia, there seem to be few reasons why you would still send letters to a friend in this digital age. If you decide to share some news in a letter with someone you already speak to on Facebook or WhatsApp every day, you end up having to sidestep the topic for days until the letter arrives.

Or you might blurt it out even before you've posted the letter, as I sometimes do.

Yet I have found it hard to let go of my mysterious attraction to the art of letter writing, a form that was already disappearing when I was growing up in the 1990s. The dawn of the Internet age was when my interest in letter-writing began.

Perhaps having spent too much time with my nose buried in storybooks, I had come to associate letters with old-fashioned detective novels and romantic intrigue. Or maybe (read: most likely) I was just an insufferably pretentious child who wanted to seem grown-up and important.

Today, an old box in my bedroom houses evidence of these early forays into letter-writing, and other miscellaneous scribblings besides. Among its contents is a packet of old-fashioned typewritten letters from a grand-aunt in Penang.

And still left in their original envelopes are handwritten letters from primary school friends whom I have kept in touch with to this day, as well as some letters and cards I for some reason ended up not sending.

These schoolgirl letters abound with earnest declarations of friendship, cheeky sketches, "P.P.P.S"es, secret hieroglyphics I can no longer decipher, and stylistic affectations as we tried to sound like Enid Blyton, Laura Ingalls Wilder, or whoever else we happened to be reading at the time.

As I leafed through them and the old diary I kept when I was about seven years old, I marvelled at how much I had changed in some ways - and how little I had in others.

I chuckled at my attempts to get back at people who were mean to me by making them the subjects of embarrassingly bad poetry.

And as I looked back on my younger, more hopeful self, I felt pangs of shame - feeling, like Simba in the Lion King, that I was more than what I have become.

It is incredible how these handwritten fragments can be such potent tissues of memory and desire, capturing the spirit of the past in more textures and dimensions than social media generally offers.

In this age of instant gratification, physical letters, sadly, seem to be receding ever further into the margins of modern life, and will likely go the way of Rediffusion and the telegraph.

Making letter-writing all the more impractical as a mode of communication is the fact that my friends struggle to read my handwriting, which tends to lapse into a kind of shorthand. So they take photos of my messages and get me to transcribe them over WhatsApp.

Still, I enjoy sending them postcards and letters when I find a spare hour. I like to think that even the most prosaic or illegible letter I send to my friends conveys the simple message, "You matter to me".

These letters, if nothing else, are tokens of affection, not least because of the effort that goes into writing them. In the words of the late Canadian professor and philosopher Marshall McLuhan, the medium is the message.

Although this is usually my main motive for writing them, I don't believe that letters, while more intimate, are necessarily more sincere. In fact, the reverse may well be true.

There has always been something performative about the act of letter-writing. It is tempting to write with posterity in mind, conscious of not just one person but a wider audience who might one day stumble upon your letters, responding with curiosity, even admiration.

I would be lying if I said the cultural currency associated with letter-writing doesn't play some role in my decision to keep going at it.

Nor am I immune to the charms of vintage stationery, and the pleasure of running my fingers over a sheet of soft notepaper that has been written on .

Could my letters be an excuse for a kind of narcissistic self-communion, a way of stamping my cultural sensibilities onto friends who would rather I shared a funny video with them on Facebook instead?

I dispel these doubts by losing myself in the ritualistic motions of letter-writing: Write uninterrupted. Fold the letter, seal the envelope, print the address, affix the stamp, and carry it to a postbox where you let it go, watching it disappear into the darkness.

On social media, we spend much time reacting to things, constructing personas through incremental likes and re-tweets - often nothing more than intellectual passiveness masquerading as activity.

Composing a well-written letter, on the other hand, demands sustained focus and discipline. You learn to dispense with the throat-clearing, and marshal your thoughts into a series of coherent paragraphs.

Online messages are easy to ignore, but we are more conscious of the space letters - and, by extension, their senders - take up in our lives. At some point or another, we have to decide what to do with them. Do we stuff them in boxes, keep them by our bedside, or burn them?

My grand-aunt and I have maintained our epistolary exchanges over the past 10 years, although e-mail has since taken over the letter as our primary - if less preferred - way of communicating. She prints out all the e-mails I send her.

There is something more substantial about a physical letter. Perhaps it offers the comforting notion that we will be less quick to forget or be forgotten.

Letters and postcards, slipped into books, or falling off the back of drawers, are easy enough to misplace. But they also have a knack for turning up when you least expect them to.

Long after the machine stops, and all forms of social media collapse into nothingness, these old letters and notes will endure. We will cling to them, for they are precious proof that once, many years ago, we existed, and were loved.

• #opinionoftheday is a new column for younger writers in the newsroom to write about issues that matter to them and their peers.