An Inspiring Word

I'm reading Frank McCourt's Teacher Man now. I first read his award-winning Angela's Ashes nearly a decade ago. In his prologue, he wrote that he is a late bloomer. His first book Angela's Ashes was published in 1996 when he was 66 years old! He also wrote:

Now I think it's time to give myself credit for at least one virtue: doggedness. Not as glamorous as ambition or talent or intellect or charm, but still the one thing that got me through the days and nights.

Doggedness.

Doesn't sound very nice but is an inspiring word ;-)