Who said "Every challenge is an opportunity to prove one's mettle."?

This quote is attributed to Gabriele D'Annunzio.

Every challenge is an opportunity to prove one's mettle. - Gabriele D'Annunzio

"Every challenge is an opportunity to prove one's mettle."

Gabriele D'Annunzio Perseverance

Poet Novelist Italian 1863–1938

"I am my own muse. I am the subject I know best. The subject I want to know better."

"The only way to deal with an unfree world is to become so absolutely free that very existence is an act of rebellion."

"Life is either a daring adventure or nothing at all."

"I love the beautiful season when the flowers bloom and the birds sing."

"Perseverance is the key to success."

"Don't give up on what you believe in."

"I've been through worse."

"You learn to live with the pain."