6 c's

76-year-old Tasuku Honjo, who is an immunologist at Kyoto University, was awarded a Nobel Prize for Medicine in recognition of an important cancer related discovery.
His motivation in life is contained in 6 words beginning with the letter 'c'; curiosity, challenge, confidence, continuation, concentration, courage.

Which of the six letters summarise your character best?

Do you have a saying or proverb by which you lead your life?