Argue for your limitations, and sure enough, they're yours.
The notion touches on an interesting concept akin to this one by Fyodor Dostoevsky:
On the shores of hesitation bleach the bones of countless millions; who at the point of victory, stopped to rest and while resting....died.
What they both imply is lack of courage to continue on, to go Further (in Jed's words), to venture into the unknown, to take that dive off the cliff, to let go the tiller, etc etc etc. The implication also, at least in the second quote, is it's a matter of life and death. In the first, it's a matter of stasis. No growth is implicit in both.
Related is don Juan's lament at the end of "Tales of Power":
Listen to that dog's barking. That is the way my beloved earth is helping me now to bring this last point to you. That barking is the saddest thing one can hear.
That dog's barking is the nocturnal voice of a man. It comes from a house in that valley towards the south. A man is shouting through his dog, since they are companion slaves for life, his sadness, his boredom. He's begging his death to come and release him from the dull and dreary chains of his life.
That barking, and the loneliness it creates, speaks of the feelings of men, men for whom an entire life was like one Sunday afternoon, an afternoon which was not altogether miserable, but rather hot and dull and uncomfortable. They sweated and fussed a great deal. They didn't know where to go, or what to do. That afternoon left them only with the memory of petty annoyances and tedium, and then suddenly it was over; it was already night.
I suspect my initial reaction to these statements was similar to most - a sense that I ought to DO, and that if I didn't DO, I was failing, stalling, showing no courage, inert, in stasis, so fuck it, let's go get drunk.
I think my take began to change when I challenged the quote from don Juan. Instead of following dJ's lead (that is, agreeing with his perception) I began to think there was a possibility he was wrong. Secondarily, and perhaps more importantly, assume he was correct, that the man's "...entire life WAS like one Sunday afternoon..." and that all he really awaited was his death...and relief from the tedium perhaps? The point is (if there is a point) that dJ presented this vignette as a negative, perhaps the opposite of how a "warrior" would act, presented the man as an "eagle snack", unaware, unenlightened, a failure.
What if instead of following dJ's lead, one were to say of the man, his life, and his dog (in similar fashion I've thought in re a heroin addict dying of an overdose), "So?" ?
What if, instead of "taking the leap of faith", etc, one decided, fuck it. I don't feel like it. Perhaps that's a more superior way to go...to trust yourself entirely, and if you do not feel like jumping, don't. Could it be these admonitions to act in order to evolve are tricks?