Alexander Fleming did not realise how important his discovery was; for a decade after discovering the penicillin mould, he focused instead on the bacterium’s potential use as a topical antiseptic for wounds and surface infections and as a means of isolating certain bacteria in laboratory cultures. It was left to his fellow Nobel laureates, Howard Florey and Ernst Chain, to demonstrate in 1940 that penicillin could be used as a therapeutic agent to fight a large number of bacterial diseases.
We tend to rewrite the histories of technological innovation, making myths about someone who had a great idea that changed the world when, in reality, that person was usually not the inventor at all but the person who knew how to exploit the idea and bring it to scale. Such was the case with penicillin, where Alexander Fleming has been credited with an idea actually discovered and pioneered by a fellow chemist from the same laboratory, Howard Flory.