A couple of years back – after I had started going to the pub at lunch, but before the morning cans began – I had sat next to a guy drinking a booze-hardened energy drink on the train into work. It was impossible to be entirely sure, but I was sure. The cloying chemical reek of off-brand energy drinks is a familiar part of the rush-hour bouquet, but he had added a few measures of harder stuff. And he looked the part, too, his shirt creased, trousers stained, eyes red and haunted, stubble undisturbed by a blade. Just about ready to give up the charade, or have it torn away from him. Not a sight to please a manager or any colleague. I hoped that lives did not depend on his work, that he was not on his way to direct aeroplanes or perform surgery. The sorry scene might have been salutary, but instead I drew a perverse lesson from it. I wasn’t that bad, I told myself. I didn’t have to worry too much. Here was living proof that there was much further to fall before the fall became final. And plenty of opportunities to change course entirely.

Bottle sloshing in my bag, I set off for the Tube.

A great heaviness had settled into my heart and my tread by the time I reached the office. I dreaded the attention my battered face would bring, the questions I would have to answer, even if they were kind. I did not have to lie about the essentials, at least. The effort to remove the bag from the tree was real and blameless enough, and I did not have to mention cockatoos or my blood-alcohol level. But I did not want to deal with people at all. I did not want anyone picking up the stench of decay from me. The prospect of the catch-up with Polly and Eddie was even worse. I had placed my last remaining hope in coming up with a convincing way to present the facts: figuring out, on the Tube, a way to tell the truth, but put an appealing spin on it. As it had turned out, all my creativity went into taking nips from my aluminium bottle in a surreptitious way while trying not to appear surreptitious. Agitated by the walk to the station, the bottle fizzed and spat in a conspicuous way when I tried to open it, and sent a trickle of foaming liquid over my knuckles. For a second I feared the whole thing might erupt in a geyser of beer, exposing my secret shame to the carriage. I had to screw the cap back on with a hard twist, and then try to release it very slowly, easing the pressure off, and it hissed and bubbled and generally made not-mineral-water noises.