(n) :
an unsought, unintended, or unexpected discovery, made by accident and
sagacity; the discovery of something by accident while investigating something quite different. For example, finding a biological culture "ruined" by mould, and discovering the antibiotic penicillin as a consequence
"serendipity is when you find things you weren't looking for because finding what you are looking for is so damn difficult. --Erin McKean,"