Tim Cook smiling.
Apple CEO Tim Cook wakes up early and starts his day by sifting through the hundreds of emails he gets from customers.
  • Apple CEO Tim Cook's day starts at 4 a.m. and is full of hourslong meetings.
  • Cook is an intensely private person but has given some insights into his daily routine.
  • He's said he reads hundreds of emails a day and is the last one to leave the office.

It takes a lot to run the world's largest company — including a very early wake-up call.