At Apple his role became implementing Jobs's intuition, which he accomplished with a quiet diligence.
Never married, he threw himself into his work.
He was up most days at 4:30 sending emails, then spent an hour at the gym, and was at his desk shortly after 6.
He scheduled Sunday evening conference calls to prepare for each week ahead.
In a company that was led by a CEO prone to tantrums and withering blasts,
Cook commanded situations with a calm demeanor, a soothing Alabama accent, and silent stares.
"Though he's capable of mirth, Cook's default facial expression is a frown, and his humor is of the dry variety,"
Adam Lashinsky wrote in Fortune. "In meetings he's known for long, uncomfortable pauses,
when all you hear is the sound of his tearing the wrapper off the energy bars he constantly eats."