Life is short, and Art long; the crisis fleeting; experience perilous, and decision difficult.

Aphorisms by Hippocrates, the very first aphorism:

Life is short, and Art long; the crisis fleeting; experience perilous, and decision difficult. The physician must not only be prepared to do what is right himself, but also to make the patient, the attendants, and externals cooperate.

A neat summation that remains true in virtually all fields today. It takes a long time to develop skills (Art long) compared to the allotted time we have to develop those skills (life is short), the pace of change is fast and we only have one chance to get it right (the crisis fleeting), the consequences are great (experience perilous) and as always the "decision difficult." The second sentence is not perhaps as crisp but is just as consequential. A good decision without support from all parties in the context (the patient, the attendants, and externals) is like as not to fail. The challenge is that in the modern era, rarely can we "make" others cooperate, rather we have to convince, motivate, or incent them to cooperate, an endeavor fraught with variable outcomes. A variability that is less and less desirable, the greater the consequences arising from the decision.

The Latin original is Vita brevis, ars longa, occasio praeceps, experimentum periculosum, iudicium difficile.