A wizard is only as good as his spells," people will often say.

A wizard is only as good as his spells," people will often say. It is
telling however, that this statement is only made by people who have never
been wizards themselves.
Those of us who have chosen to pursue a sorcerous career know that a
knowledge of spells is only one small facet of the successful magician.
Equally vital are a quick wit, a soothing tongue, and, perhaps most
important, a thorough knowledge of back alleys, underground passageways, and
particularly dense patches of forest, for those times when the spell you
knew so well doesn't quite work after all.
-- The Teachings of Ebenezum, Vol. I