Photo source: Wikimedia Commons, Nobel Foundation
Alexander Fleming (1881-1955) was a Scottish microbiologiest best known for discovering penicillin. Wikipedia says,
"On September 3, 1928, Fleming returned to his laboratory having spent August on holiday with his family. Before leaving, he had stacked all his cultures of staphylococci on a bench in a corner of his laboratory. On returning, Fleming noticed that one culture was contaminated with a fungus, and that the colonies of staphylococci immediately surrounding the fungus had been destroyed, whereas other staphylococci colonies farther away were normal, famously remarking, 'That's funny'... Fleming grew the mold in a pure culture and found that it produced a substance that killed a number of disease-causing bacteria." (Wikipedia: Alexander Fleming, 8.19.21 UTC 20:44)The rest of this post is some quotes from Fleming.
Scientific discovery
"When I woke up just after dawn on September 28, 1928, I certainly didn't plan to revolutionize all medicine by discovering the world's first antibiotic, or bacteria killer... But I guess that was exactly what I did." (AZQuotes.com)
"The unprepared mind cannot see the outstretched hand of opportunity." (AZQuotes.com)
"...never neglect an extraordinary appearance or happening. It may be - usually is, in fact - a false alarm that leads to nothing, but may on the other hand be the clue provided by fate to lead you to some important advance." (Quoted in Molecular Cloning by David Russell and Joseph Sambrook)
"For the birth of something new, there has to be a happening. Newton saw an apple fall; James Watt watched a kettle boil; Roentgen fogged some photographic plates. And these people knew enough to translate ordinary happenings into something new." (Quoted in The Life of Sir Alexander Fleming by Andre Maurois)
"It is the lone worker who makes the first advance in a subject: the details my be worked out by a team, but the prime idea is due to the enterprises, though, and perception of an individual." (Speech at Edinburgh University, 1951)