Tell them to look around the company, look at the miserable look on people's faces. Drag them into a meeting or status review. And you get bonus points if you bring them along to the HR meeting you have if you get laid off, or "the talk" with your manager/director about VSP...
Remember the first impressions on a kid is always the lasting impression. I'm going to do this the week right after school ends in the summer. It's fitting, because my kid is still all happy after he won 1st place in one of the science field day competitions. I better do something about it before he gets the wrong idea of actually thinking this should be a career instead of just a fun hobby....