It is one thing to plan, another to execute. How can it be otherwise? The plan rises before the mind’s eye, captivating by its beauty and originality; takes no account of the frequent falterings which one must feel in essaying an untried path, allows nothing for interruptions from sickness, sorrow, or fatiguing professional pursuits, takes not within its ken the contingencies of life, the occasional procrastination in which the mind will indulge, and the disadvantages which distance from the press, disjunctness of publication, and the imperative demands of the printer’s familiar, may concur in producing.
Source: wiktionary