A wise pilot once made this fact very evident to me:

As pilots, we fly airplanes. At the end of the trip, we walk out and leave the airplane on the ramp. It does not follow us home, we do not bring the paperwork back to review, we are not assigned to fix things or create special projects. You don't think very much about your job until the next duty start time.

How many other jobs do you know where nothing is ever brought home? Answer: Not very many, and certainly not an accountant or engineer.

What to say: tell your parents you value quality of life over the money and while you realize the hardships involved you are prepared to accept them and make smart financial decisions along the way.

That's a start anyway, hope it helps.