Persevering seems to be a very personal choice and there's no correct decision for everyone. It's easy to look at someone who hasn't achieved the level of succe

Persevering seems to be a very personal choice and there's no correct decision for everyone. It's easy to look at someone who hasn't achieved the level of success they desire and to write them off while encouraging them to take a safer, more conventional path. The trouble is that such a decision all but guarantees their ambition won't be realized. It seems that those who are just happy doing their thing are the ones most apt to persevering. They also seem like the ones who would feel more disappointed by giving up than by having not "made it" yet. At what point would you call it a day? Is there some point you can determine it's worth giving up? I'm curious to know how you'd make such a decision.