Alexander Fleming, a Scottish physician at the St. Mary’s Hospital, London, made two epoch-making discoveries, lysozyme and penicillin. But contrary to popular fables, the events were not that serendipitous. He was already an established microbiologist and it took him dogged labours to vindicate his discoveries. He simply had the right mind. Penicillin was especially a hard nut to crack upon which he toiled for half a year with his associates just enough to make a convincing conclusion on the antibacterial property. He in fact utterly failed in understanding what it actually was. As he himself unpretentiously stated: “I did not invent penicillin. Nature did that. I only discovered it by accident.” But that did not debar him for sharing the 1945 Nobel Prize in Physiology or Medicine with Howard Florey and Ernst Boris Chain, who isolated the compound and worked out the medicinal applications. Strangely, Fleming’s biography has been presented in bits and pieces on the crucial elements of his discoveries, and usually contradictory. This chronicle is trying to mend the gaps and broken pieces in the historical records.