What does joe martin say are the four questions we must answer for ourselves?

The four questions are
If serving your college was a crime, would there be enough evidence to convict you?
If your paycheck was determined only by your serving, how long would you survive on it?
If everybody was like you, would people quit their jobs?
Do you brighten up a room when you enter it or when you leave it?

By asking these 4 questions, we will know the truth about our current situation and find a proper way to handle all of our problems, rather than having to make excuses all the time.