Insecurity

In Hold Still, Sally Mann writes, "And then, as often happens to me, the self-doubt that had dammed up so much behind its seemingly impermeable wall allowed the first trickles of hope and optimism to seep out, and through the widening crack possibility flooded forth. Insecurity, for an artist, can ultimately be a gift, albeit an excruciating one."

I've read that last sentence many times, turning it over and over. Whenever insecurity appears in my writing life, it generally cuts into my productivity and the quality of my writing, so I wouldn't call it a gift. But is there a post-insecurity rebound, a feast to follow the famine, as Mann describes?

Writers can turn almost anything into fodder for work, even insecurity, so there's that. Does self-doubt serve other purposes--not just by keeping us humble, but by prodding us to certain questions and self-examination that we might otherwise skip?

As you can probably tell, I'm thinking a lot about this.