The teacher’s eyebrows shot up. And all the other eleventh-graders in his class were suddenly free to dream because my son had given them permission to do so, and their futures percolated up into a froth of exciting possibilities. Why? Read on.

It was 2001, and my son’s 11th-grade math class was sweltering through the last summer days of the school year. All of the assignments for the term were done, finals were ongoing, and his math teacher decided to use this time to try to give them some practical learning they could use in real life. So he assigned the class an exercise: It’s several years later, after your schooling is done. What are you doing for a living? They were to decide how much they made and submit a budget.

My son Jon thought this was a great idea, and came home full of enthusiasm. Although he did not call it “reverse engineering,” he decided on what sort of life he’d like in ten years and counted up how much things would cost. Then he’d decide on a career to support that lifestyle.

“Well, I’d like to me married,” he mused aloud to me and his grandmother. “I’d rather my wife didn’t have to work, and I want three kids. Hmm.” He chose where he wanted to live, in the foothills of the mountains, what sort of house he’d live in, and what sort of car he wanted to drive (it had to be AWD due to those mountains, especially in icy conditions.) He chose where he wanted to work and how much the commute and maintenance costs of the car would be. And would his wife want the family to have a second car? Of course she would. So he budgeted for two car payments. He looked up house prices, calculated his mortgage and utilities.Calculated how much food would cost, including occasionally taking his wife out to dinner. We looked it over.

“Did I forget anything?” he asked his mother and his grandma. I suggested medical costs. I helped him allow for health insurance, deductibles, etc.

My mother just had one word. “Taxes.”

His face fell. “Oh, that’s a big one–how could I have forgotten that?” Income taxes and real estate taxes got factored in. “They’re going to take a third of my paycheck?!” Yes, son, they will.

Once he had a total figure–I think it was around $150K/yr–he started looking in the New York Times want ads for jobs that paid that well. Some of those required insane amounts of time and money to pursue advanced degrees, so he crossed them off his list of possibilities.

“So I guess I will have to be a medical devices salesman,” he decided.

The next day, in math class, his classmates stood up there with their lackluster lives budgeted out. One was going to be a legal secretary. One was going to be a teacher. Most of them had chosen office work. All of them were safe, expected careers.

Then my son stood up to make his presentation. As he worked through his figures and estimates the class got more and more excited. The teacher’s eyebrows shot up. And all the other eleventh-graders in his class were suddenly free to dream because my son had given them permission to do so, and their futures percolated up into a froth of exciting possibilities.

Their teacher poured ice water on this. “Whoa, whoa, whoa–wait a minute! Let’s set some parameters here! Do the exercise again, tonight, but you can only make… ” I think he set it at $35K a year.

My son Jon turned to his best friend, who was in that class, and said sotto voce, “Well, there go the wife and kids.” But the two of them did the assignment together, budgeted as roommates sharing an apartment, and still kicked the rest of the class’ butts with their projected lifestyle.