I say, "If you do what you love with elan and determination, and don't worry about 'making a living at it', eventually you will 'succeed'."
"Easy for you to say," says the spokesperson for all those in despair over their careers. "You are the child of privilege, plus you got lucky."
"This is true," I confess, "but my way was never easy. I had to work hard at what I loved, and I never gave up, in spite of many challenges."
"What do you know of 'challenges'?"
"What do you know of my life?"
The argument goes on to compare the merits of "doing what you love" right now versus working all your life at a job you hate, in order to save enough that you can retire at 65 and then "do what you love".
This elicits the response, "Retire? I will never be able to retire!"
Here's the problem: neither debator can imagine the other person's life experiences, and there is no argument that can convince either of the validity of the other's point of view.