Monomania

mo-no-ma-ni-a (mn-mn-, -mny)

noun
1. Unusual or even pathological obsession with a single thing, usually a subject or an idea.
Novelists must suffer from some degree of monomania in order to think about an idea long enough to write 350 pages about it.


Synonyms: dedication, devotion, enthusiasm, extremism, fever, furor, immoderation, infatuation, madness, obsession, obstinacy, one-track mind, preoccupation, zeal.

* The passage quoted in this definition is from Monomania: the flight from everyday life in literature and art by Marina Van Zuylen.