"Vita brevis, ars longa, occasio praeceps, experimentum periculosum, iudicium difficile."
That is the Latin translation of Hippocrate's first sentence in his medical text, "ars" - art - meaning the craft of medicine, is slow to learn given the brevity of life. I think the quote has been often misunderstood and misapplied.
It has always been interesting to me that the etymology of our use of "art" refers to "craft."
English: "Life is short, and (mastering a) craft slow, opportunity fleeting, experimentation perilous, and judgment difficult."