A man joins a big corporate empire as a trainee.
On his very first day of work, he dials the pantry and shouts into the phone, "Get me a coffee, quickly!"
It turns out that he didn't dial the pantry at all.
The voice from the other side responded:
"You fool! You've dialed the wrong extension! Do you know who you're talking to, dumbo?"
"No," replied the trainee.
"It's the CEO of the company, you fool!"
The trainee pauses for a moment to think about an appropriate response. He shouts back, "And do you know who YOU are talking to, you fool?!"
"No," replied the CEO indignantly.
"Good!" replied the trainee, and puts down the phone.