The first time I saw Alex she was scribbling furiously in a book. The second time she was doing the same, her pen skimming across the page. On the third occasion I went and asked her what she was doing. At that point she looked up, surveyed me and focused back on her book where she carried on as before. I followed her lead and, upside down, saw her write what I had just said.

It turned out that she was trying to write down every conversation she was involved in. But this was before she had learnt any decent method of shorthand, so she wrote everything in longhand with just a few abbreviations as and when they came to her. It didn’t seem like it at the time, but the fact that she had recorded my question was a positive sign.

I sat down at a nearby table and drank my coffee and after a few minutes she came over to apologise for not answering my question earlier. She had to finish off a previous conversation while the memory was still fresh she said. That was when we talked properly for the first time. Halfway through, after she’d explained her project, I asked her why she wasn’t writing down this one. She said she would remember it and write it down later. It was the closest she ever really got to saying something romantic. Some time afterwards I found the book where she’d recorded it and she had remembered it just as I had.

Later she would hone a much better technique, but at the point I first approached her the weight of letters was starting to bury her so she had taken to evaluating a new contact before working out whether the conversation would be important enough to record.

Each person was given a number in a cycle of 1 to 99. I was one of many 27s. If they turned out to be enduring contacts they would gain a two-or-three-letter acronym to distinguish them, which might or might not equate to their initials. Eventually I became FB. The second letter stood for boyfriend, but she would never tell me if the initial F was for first, of fifth or even fourteenth, though I never had any reason to think the second or third option was likely. After we split up I remained FB and never heard of any SB.

She had been doing her writing for about nine months when we met and her project to record everything she said to anyone and everything that anyone said to her was already starting to override all else in her life. Friendships were becoming unworkable, family relationships tense.

Her apartment was filling up with the accumulated tomes of her conversations. Volumes of notebooks lined the corridors or were in boxes, all carefully categorised. They were her ‘day books’ where she’d jot down the conversations as she was having them. Depending on what she was doing and how big or small the notebook was, she could get through more than one in a day. The most she ever completed in a single 24 hour period was three and a half. There were other books where she would analyse the conversations. This was before she got a computer.

Numbers were important to Alex. All the conversation logs were mined for information: how many words she spoke in a day; how many were spoken to her; how long it took for each conversation to run its course; how many words beginning with A, then B, then C; the average number of syllables in a word; the proportion of sentences, words and syllables spoken to her versus those uttered by her.

She never fully explained to me why she had started doing all this, although one night she told me that she was looking for patterns which she could extrapolate into bigger truths. She was sure the habits of individuals would be replicated by society as a whole, by all of humanity even, and it shouldn’t change much over time. The problem with such conversations was that she was writing them down as we were having them, which made the exercise all rather circular and that became her reason for not talking about it anymore. She could have decided not to record those conversations, but she didn’t want to do that. Either way it would unfairly skew the data she said.

When we were first going out we had a pact that anything after 10pm would go unrecorded, not so much to preserve any secrets or intimacies, but just so we could have some normal time together for at least part of the day. I started timing my visits to her place to coincide with this watershed but after just a couple of months she reneged on it and insisted on writing or taping everything that went on.

We split up not long after that, but I kept in touch fitfully. It was easier to do so on the phone or email, when the notebook wasn’t so apparent or intrusive. I didn’t see her often.

She still managed to go out of the house and interact fairly normally, often with a recorder rather than a notepad and pen and she’d transcribe everything when she got home. As time went on she developed a method of writing up her conversations that now leaves them all but incomprehensible. She rejected the notion of words for being too time-consuming to write down and instead focused on the first letter and the number of syllables in any word. I don’t know how but she seemed to intuitively grasp how many there were in a word without having to think about it. Pages of her books were filled up with strings of letters and numbers like “a3 b4 c1 n1...” and so on and on and on. A litany of algebraic equations with no solution; conversations that had now gone quiet. She wasn’t big on capital letters but there was some basic punctuation.

According to a few of her calculations that I came across, on average five per cent of all words of three syllables or more were misused by people in conversation – with a high of around nine per cent for words with five syllables and less either side of that. Conversations were longer towards the end of the week but with a higher proportion of shorter words. Those can’t have been the only results she came up with but I can’t find any more.

Her notation system meant she started using fewer notebooks which took up less space, but the intelligibility declined precipitously and were lost to anyone but Alex, who seemed to be able to remember the conversations and work out the words in context. It made her computation of conversational statistics easier of course.

The only way for anyone to figure out what the books refer to is if Alex kept the recording of the conversation, which she did with increasing regularity as her project went on and technology improved. At first she’d use a cumbersome portable cassette tape deck, but later she would carry around a small digital device. Any recording I’ve listened back to and compared has matched perfectly to her codified transcription.

She was in the process of transferring everything – all the conversations and all the recordings – to a computer and was working backwards through them, charting everything and comparing it to the previous statistical results as she went. I can now hold the contents of almost 5,000 notebooks in the palm of my hand on a little memory stick.

When we were dating I would watch her try to make sense of everything she had compiled. She worried sometimes about the results that stared back at her. For a while people were speaking far more to her than she was saying in reply and she was concerned that, if everyone followed this route, the world would soon turn silent as people said less and less in reply to any sentence. But then she thought about the reverse. What if everyone in the world said more than was said to them? This was the majority of people she had been interacting with after all. The world could die in a cacophonous avalanche or run out of time to say everything that needed to be said.

Then one day she decided to just go quiet. Any conversation would just make matters worse one way or the other. She refused to go out, she disconnected her phone and sealed her letterbox. She spent several weeks just allowing herself to wither inside her flat. I still had keys from our abortive relationship so I was the one who found her.

The nurses encourage me to speak to her when I go to visit, or at least read to her from a book, but she can’t reply even if she wanted to and I know a one-sided conversation would just infuriate her, so I just sit there silently by her bedside for a few hours every day. Sometimes while I’m there I write down what I would like to say to her. In fifteen years I’ve filled 1,782 notepads. They’re all stored in my flat but I’m starting to run out of room. I might stop soon.

If she ever wakes up and leaves this place and sees all the books and asks what I’d been doing, what I’d been writing about, this is what I’d tell her.