I first became familiar with Dan Pink while watching one of his TED presentations online.
He writes a great blog post about the difference between failure and mediocrity. Here it is:
Most people are more frightened of failure than of mediocrity. It should be the reverse.
Failure is a broken leg — painful, but easily fixed. Mediocrity is a creeping disease — invisible and insidious — that disables so completely that there’s often no recovery.