Buying books is fun, with a glass in your hand

Before I first acquired a Kindle, exactly one year ago, I didn't usually buy books while under the influence of alcohol. I won't say I never did it, because that would be a lie. But it wasn't a habit. After a couple of glasses of wine, I tend to fixate on the present. I have no use for five to seven days' delivery time. The Kindle is wonderful for drunk people because you can climb into bed, press one button, and The Anatomy of Melancholy instantaneously materialises before you, plucked by the so-called Whispernet out of the surrounding ether.

The number of books I buy while sober is, I have noticed, inversely proportional to the number I buy while drunk. It's a zero-sum game, as Proust once observed of wet dreams: when all the resources are consumed in the night, none are left for waking life.

Counting free samples and e-books from the pre-1923 copyrightless domain, the total number of books I "purchase" per month has actually gone up by about 200%, while the number of books I purchase while sober has dwindled to about 5% of the total. You used to be able to say that someone's library looked like it had been assembled by a drunk person. Now, for me, the metaphor has become a reality. How does a drunk person's library differ from a sober person's library? There are probably as many answers as there are drunk people, so I can only speak for myself. Here is my personal breakdown of how the symptoms of intoxication correlate to book-buying practices:

1. Lowered attention span. This means I order a lot of free samples. As a former destitute graduate student, I still have a lively interest in free stuff. In fact, free samples were the feature that initially got me hooked on the Kindle. For an entire summer, I read almost nothing but free samples. Sometimes, when I had particularly enjoyed a free sample, I considered buying the book. I gave a lot of thought to these decisions, but invariably ended up just ordering another free sample.

2. Poor short-term memory. This means I usually don't remember to buy the book the next day, either. Also I "buy" a lot of huge Victorian novels, which are free, lose track of the characters' names, and never finish them.

3. Sentimentality. I am a sentimental, rather than angry, drunk. One night, having coerced the cat to sit on my lap, I proceeded to read free samples of four different memoirs by scientists who form unlikely and ultimately tragic bonds with research animals.

4. Decreased inhibitions. Until technology empowered me to order books while drunk, I didn't realise the scope and diversity of literature that I wasn't reading purely out of embarrassment. To name just one genre, many off-colour books that were recommended to me over the years by boyfriends and crushes have now found a home on my Kindle: Marcuse's Eros and Civilisation, Miller's Sexus, Plexus, Nexus, Dworkin's Intercourse (I'm not making that up), Fanny Hill: Memoirs of a Woman of Pleasure (that one, published in 1748, is actually great, and free).

5. Impaired judgment. I order a lot of books that I'm just clearly never going to read without the help of substances I don't abuse yet. Example: Phenomenology: A Very Short Introduction.

A few months ago, my drunk reading tendencies converged upon a single author. The Kindle actually made the suggestion itself, in the form of one of its standard issue author screensavers: a portrait of Agatha Christie that I found staring up at me, half-obscured by a pile of bills. She was represented, as always, as elderly, wearing a scarf with a brooch, her gray perm etched in meticulous detail. Beneath remarkably heavy brows, her eyes were shrewd and weary, as with the knowledge of countless unravelled mysteries.

The last time I had read Christie novels with any regularity was between the ages of 10 and 13, when I used to borrow them from my mother's little sister, the most beautiful and lively person in my family, then in her 20s. I read them obsessively, one after another, either despite or because of how much they frightened me. Although the style was simple and readable, not unlike that of the Baby-sitter's Club books, and although the detectives, Miss Marple and Hercule Poirot, were twinkly, grandparental types, nevertheless, everywhere these gentle souls went, someone was killed in hatred.

Suddenly I was seized by a desire to revisit Poirot, the charming Belgian with his weird moustaches. Thirty seconds later, I had clicked on "Buy now". Death on the Nile cost only $5.99 – four dollars less than a new release – and there would be no physical book to reproach me the morning after.

Because I am a writer, people sometimes ask me how ebooks have changed the literary landscape. The short answer, for me, is that I have developed a compulsion to drunk-dial Agatha Christie several times a week. The Poirot mysteries, which initially seemed to me to rush by too fast and leave nothing behind, are, I find, perfect for a drunk reader with a decreased attention span. The undazzling writing style now seems to me to correspond, profoundly and even ingeniously, to the plot: despite an unassuming, even banal or ridiculous appearance, the detectives work in unfathomably deep ways. Sceptics call Miss Marple fluffy and dithery; they call Poirot senile and gaga – but, again and again, the fluffy and the gaga triumph over Scotland Yard and the most deceptive criminal masterminds. In this sense, despite the profusion of corpses, Christie's novels are all about cheating death. The time has come for age to claim Marple and Poirot – but age never does claim them. Decrepitude is endlessly thwarted by ingenuity.

Reading Agatha Christie novels now, as a drunk person, with impaired judgment, lowered cognitive capacity, and decreased short-term memory, I no longer try to guess the killer's identity in advance. When I was 11, I was constantly trying to outthink Poirot, with miserable results. This added an unpleasant degree of tension to the reading process. Now, my pleasure in Christie is entirely passive. I know I can't solve the mystery, and why should I? Possibly because of my chemically acquired poor short-term memory – drinking, I realise, makes you old – I have also grown to enjoy the stereotypical characters.

For the past few months, with the exception of work-related books, I have barely read anything at all except Poirot novels. When I'm sober, this worries me a bit. I recently confided this worry to a colleague, who, in an attempt to make me feel better, pointed out that, in the greater scheme, drunk-dialing Agatha Christie isn't such a terrible vice. "You could be on Ebay, buying sectional sofas," she observed: a remark which opened a brief, vertiginous vista on to the field of possible dependencies that might lurk in my future. Adderal and Proust? Cocaine and Very Short Introductions? The prospect troubled me for the rest of the afternoon. But at the end of the day, when I uncorked a $7 bottle of Viognier and turned on the Kindle, a wave of well-being washed over me. I opened up Death in the Clouds, in which Poirot investigates the death of a wicked Paris money lender, in an aeroplane, by poison-tipped dart. Luxuriating in the measured accumulation of banal small talk and abstruse clues, I reflected comfortably that I had still only read 32 of the 34 Hercule Poirot novels. What problem awaits me next? Time will tell.

If there's one thing I've learned from Agatha Christie, it's that there's no point trying to guess the end.