How come a Martini is a cocktail but a gin and tonic isn’t? Nobody ever asked for a G & T to be shaken not stirred, nor wrote a book on how to make a perfect one, nor bored a bar rigid on the perfect sort of glass for one but in every essential way they are the same. The same number of ingredients, the same level of difficulty, but one is a drink that your eleven-year-old could mix and the other is a cocktail that you need to have a lifetime’s experience to even contemplate in your own home. Far safer to let the professionals deal with it. Like the eunuch in charge of the harem used to say, ‘this doesn’t add up’.