St. John Climacus
“Like the sun which shines on all alike, vainglory beams on every occupation. What I mean is this. I fast, and turn vainglorious. I stop fasting so that I will draw no attention to myself, and I become vainglorious over my prudence. I dress well or badly, and am vainglorious in either case. I talk or I hold my peace, and each time I am defeated. No matter how I shed this prickly thing, a spike remains to stand up against me.”
Source: St. John Climacus, The Ladder of Divine Ascent