Late in the afternoon, while still at work, I can smell hops coming off a fresh pint of beer. The scent is so strong it feels almost real. I don't work in a pub. Or a brewery, although the thought is increasingly tempting.
'Muscle memory' comes to mind - the reflex in the brain that helps you to drive using the correct physical inputs for clutch and brake, time after time. To return to your car after a two-week holiday and drive it as smoothly as you did before you took off for the sun.
Clearly I have that, because while my hatchback is used sparingly, it never feels odd. But I appear to have 'beer memory' too, which is akin to 'beer o'clock' and comes from a sensory recollection; if my nose and taste-buds don't get their longed-for fix for a while or two they start to re-create the sensations of their own volition. It's both comforting and unsettling. Two thirds of the former, one third of the latter.
The first thing I did today, before writing these words, was buy three bottles of Goose Island IPA from Waitrose. Brewed in Chicago, it's not the finest American IPA in my opinion, but it's stocked by Tesco too, and both supermarkets sell it at a lower price than specialist off licences. I've had it a few times before, but want to confirm what my palate was telling me the last time: that it's as malty as it's hoppy, and therefore not an IPA at all. That's going a bit far, actually, but it satisfies my league table instincts.
Hops, by the way, while giving a beer its bitterness and fruitiness, also act as a preservative, and so the original India Pale Ales were heavily hopped to help them survive the 19th century journey by sea from England to the Subcontinent.
Such items of knowledge have turned into a kind of mantra, and so there must be train-spotters with fewer anoraky symptoms. My life, meanwhile, has become about malt. And yeast. And water. And hops. And the strange, wonderful alchemy that enables tastes as diverse as mango and black coffee, liquorice and pine needles to be contained in different glasses of beer. From those four basic ingredients, a wonderful smorgasbord of flavours ensues.
I have, however, become a little worried about my drinking.
What's the largest number of pints you've sunk in a single day? My record is 13. We started late morning and continued until closing time. A couple of them were over food in Brick Lane; fiery curries doused by ice cold lager. For the most part, though, it was good old-fashioned binge drinking; ale for the sake of ale; a great British tradition.
Sometime after that, the beer became more important. I turned into a compulsive taster, unable to see something I hadn't tried before and not give it a go. After work, I would pop into The Harp in Covent Garden, with colleagues, or alone with my iPhone, sampling a new brew and looking it up on ratebeer.com.
Which sounds a little sad. But it's really, genuinely (mostly) about taste. If you've never tried Dark Star American Pale Ale, then I urge you to find it and savour every last drop. At 4.7%, it's very downable. The hops are zesty and citrusy, with enough bitterness to make your palate spring to attention after a long day in the office.
One of my friends said: "It doesn't taste like beer."
But the point is that it tastes exactly like beer. A very hoppy, fruity beer, which almost resembles a pint of grapefruit juice, but beer nonetheless, made from malt, water, yeast and hops.
What my friend meant was that it doesn't taste like a classic English bitter. While there are lots of pleasant English bitters, though, it's merely one style among many.
At the other end of the scale from that Dark Star pale, the same four ingredients come together to produce Kernel Brewery's Imperial Brown Stout, which has such deep flavours of coffee and dark chocolate you feel some of both must have been added. But Kernel's Evin O'Riordan tells me only the four standard items are used. It's 10.1%, and based on a recipe from 1856. If it was sold in pints back in the 19th century, there must have been some very merry dockers rolling around the South Bank.
And there-in lies one of the concerns about my drinking. A lot of craft beers are pretty strong. I've never seen a Kernel brew below 5%. Alcohol helps to deepen flavour - it 'holds' the taste. And gets you pretty drunk.
But there are some lower percentage beers with plenty of flavour too. They are, in a sense, the holy grail of brewing. Dark Star's Hophead (3.8%) and Magic Rock's Curious (3.9%) fit the bill. Both are hoppy and flavoursome to an extent you wouldn't expect at such low ABVs. Perfect for after-work, a few can be quaffed while leaving one's legs in full working order.
Falling in love with beer is a bit like falling in love with a wilful, manipulative mistress. You know she'll lead you astray from time to time, not always turn up as expected, sometimes leave you with a stinking hangover the next day and maybe a few regrets. But you keep going back, time after time, because the pleasure is too much to ignore.
You can't see her every day though. Well, you can, but your health will suffer. So, after a lot of seven-day drinking recently, I'm now willingly submitting to the nanny state's advice and having at least 48 teetotal hours a week.
But on holiday, all bets are off. America is the capital of craft beer. In Colorado, there are said to be a hundred breweries in one particular square mile. My favourites are made in California though. From San Francisco to San Diego, there are wonderful pale, amber, and dark beers being brewed.
I simply have to go on a beer tour of the United States. My liver can recover when I get back.