I worked in the film business for many years, and know the tough schedules of getting up early in the morning and long, long days going on late into the night, no wonder he's tired! Steven obviously hasn't got the energy he used to have!!
In your mind you think you are still 20 , and can still do the things you did at time in your life. But in reality you're not!
This comes, unfortunately with age, and I know how he feels!