This falls in the category of:
What They Don’t Teach at Detective School.
Flâneur (feminine, “flâneuse”) translates literally as a loafer or a person who loiters, but the poet Charles Baudelaire defined it as a passionate observer.
“There is no English equivalent for the French word flâneur. Cassell’s dictionary defines flâneur as a stroller, saunterer, drifter but none of these terms seems quite accurate. There is no English equivalent for the term, just as there is no Anglo-Saxon counterpart of that essentially Gallic individual, the deliberately aimless pedestrian, unencumbered by any obligation or sense of urgency, who, being French and therefore frugal, wastes nothing, including his time which he spends with the leisurely discrimination of a gourmet, savoring the multiple flavors of his city.” (Cornelia Otis Skinner, Elegant Wits and Grand Horizontals, 1962, Houghton Mifflin, New York)
The essential elements of the flâneur are also the essential elements of being a good investigator, reporter, researcher, and any other job that requires a well-developed ability to observe and report.