Happiness requires courage, stamina, persistence, fortitude, perseverance, bravery, boldness, valor, vigor, concentration, solidity, substance, backbone, grit, guts, moxie, nerve, pluck, resilience, spunk, tenacity, tolerance, will power, chutzpah, and a good thesaurus.

Life 101: Everything We Wish We Had Learned About Life in School--But Didn't (ed. 1994)