When I first joined the wine industry some 16 years ago, I was thrown in at the deep end specialising in selling the world’s finest wines to the well-heeled customers of Northwest London. In those early days, one of the topics that frequently plunged me under the water was when I had to sound knowledgeable about Italian wines. In my first couple of weeks on the job I was given a great piece of advice by one of my seasoned veteran colleagues: if you know just one