The greatest enemy of the self is the self.
I have learned this keenly these last few months which have included an unexpected layoff from a job that I was very good at, followed by a whirlwind job search that included 25 interviews in a forty-five day period, which resulted in a new job that I was very excited about.
I have been performing this new job for all of two weeks now and yet I spend so much time fearful that I will fail.