“Beware of the man who won't be bothered with details.”

Source: Things Fall Apart (1958), Chapter 11 (p. 95)

Chapter 124 http://books.google.com/books?id=61W3aGvTVgIC&q=%22Beware+of+the+man+who+works+hard+to+learn+something+learns+it+and+finds+himself+no+wiser+than+before%22&pg=PA281#v=onepage: Frank's Ant Farm
Cat's Cradle (1963)

Source: Cross

As quoted by Leonard Sweet, The Greatest Story Never Told http://books.google.gr/books?id=KuTRcjWL91AC&dq=, section: "The Gift of Lyrics", Abingdon Press, 2012
Variant: "Beware the man of one book."
See also: Homo unius libri
Disputed
Variant: I fear the man of a single book.

Pt. I, line 999–1005. Compare Publius Syrus, Maxim 289, "Furor fit læsa sæpius patientia" ("An over-taxed patience gives way to fierce anger").
Absalom and Achitophel (1681)
Variant: Beware the Fury of a Patient Man.
Context: Oh that my Pow'r to Saving were confin’d:
Why am I forc’d, like Heav’n, against my mind,
To make Examples of another Kind?
Must I at length the Sword of Justice draw?
Oh curst Effects of necessary Law!
How ill my Fear they by my Mercy scan,
Beware the Fury of a Patient Man.

Source: Notebook of a Return to the Native Land

#83
1900s, Maxims for Revolutionists (1903)