but I take your point
And I take yours too of course (you have one of my "Fac Res Difficila" challenge coins right? If not, let me know and I'll bring one to dinner... week after next I guess).
I definitely get the point of the quote and don't disagree, but at the same time, I think one of my biggest weaknesses is not knowing when to quit. I've been trying to get better at quitting :-)
The tough part is being able to see when it's worth pushing on and when one should quit. I err in both directions, that's for sure.
Marc Twight, one of the great American mountaineers, coined (AFAIK) the phrase "failing upward." Failing upward is when you should have quit, but didn't, and your only way to extricate yourself from your decision, is to go to the top. He calls it failing upward because he would say anytime you have lost control of the situation and your only option is a high-risk run for the summit, you've "failed upwards." I find that a helpful heuristic.