|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
Robert Louis Balfour Stevenson (13 November 1850 - 3 December 1894) was a Scottish writer who wrote thirteen novels, as well as a number of collections of poems, essays, and short stories. Stevenson was a literary celebrity during his lifetime.