Merlin's Blade: A Question

In Merlin’s Blade, author Robert Treskillard portrays Merlin as a young man left deeply scarred and half-blind by a wolf attack.

Though frustrated and often hindered by his poor eyesight, Merlin also discovers his half-blindness could be a strength as it provided a certain measure of protection against the stone’s bewitching power. This in turn enabled him to do what others could or would not.

What was true for Merlin is also true for us. When have you seen a perceived weakness, flaw or restriction provide unexpected protection or even strength?