I had to think ahead. How much would I really enjoy committing five or seven years to working on this? When you're an unemployed actor offered a TV pilot, no matter who you are you're tempted by the good hunk of change to be made. It keeps you out of the unemployment line.
An actor is totally vulnerable. His total personality is exposed to critical judgment - his intellect, his bearing, his diction, his whole appearance. In short, his ego.