Fans of Roald Dahl’s 1982 children’s book The BFG know that the whimsical work is dedicated to Dahl’s daughter, Olivia, who died from measles encephalitis when she was seven years old. However, New York Magazine’s Melissa Dahl writes that the cheerful tale was also inspired by another somber story: Dahl’s first wife’s battle to speak after she suffered a series of strokes.

In a 2015 issue of The Lancet Neurology, writer Peter Ranscombe details a speech given by neurologist Tom Solomon, who serves as director of the Institute of Infection and Global Health at the University of Liverpool. At the Edinburgh International Science Festival, Solomon described how Dahl’s first wife, Patricia Neal, had a hard time conjuring words after the strokes damaged her parietal lobe—the part of the brain that interprets letters and words, among other functions.

Because of this, she’d often ended up saying meaningless phrases, like “porteedo” instead of “torpedo” or “muggled” instead of “confused. And Dahl included some of these neologisms into The BFG, peppering the work with lighthearted nonsense words that had much more serious origins than his delighted readers ever realized.

[h/t New York Magazine]