One of the many such phrases that pepper the dialog of
DeForest Kelley's Dr. McCoy. If your basic low level trek nerd does not know the precise episode this comes from, or at least remembers watching it, then they at the very least know who said it. (By low level here I mean that they have watched some
Star Trek and enjoyed it) Even in the rest of the public you'll find people who can attribute the phrase to the series, though probably to
Dr. Spock.
The phrasing, in many ways, is meant to keep a lid on the Mary Sue-ishness of some of the supporting cast on Star Trek. Dr. McCoy always made it, even when it came down to surgery on species he'd never encountered or synapse by synapse neurosurgery, he never loses patients. In much the same way, his engineering double with a funny accent, Mr. Scott always manages to keep that old bucket of bolts in top performance. In a way, the episode in which he makes this statement marks one of the major achievements of McCoy's career and this phrase is meant to build on the humility of the character.