My grandfather–my mother’s father–was a bookkeeper for J.P. Morgan. This was back in the days when even a brokerage house of that magnitude that needed enormous armies of men to perform its calculations, hunched over their desks with their sleeves rolled up and green eyeshades on. At least that’s how I assume it looked. I’m also imagining they were spurred on by a guy in a ringleader’s outfit and handlebar mustache cracking a whip. That’s probably inaccurate.

I don’t know if my grandfather was made for the job or the job made him. I do know that his house was filled with math. As a product of both his profession and The Great Depression, he constantly calculated how much money he spent and how much he saved. Every box and can of food in his pantry had notations on its price sticker to demonstrate how much money he’d truly spent on it after coupons and sales. His cars always had little notepads with logs of when he filled up the tank and the mileage at the time. I had one in the glove compartment a car I inherited from him, until some hellbound monster stole it.

I’m sure his job paid a decent wage for the era, but he also had six kids to feed and put through Catholic school. So one year, he thought up an idea to make some extra cash: He would do taxes for people in his Brooklyn neighborhood. There was really nowhere else in the area for people to go to for such a service. No accountants, no notaries, not even many banks. He saw a void and hoped to take advantage of it.

After some advance scouting, my grandfather managed to strike a deal with a laundromat at the corner of DeKalb and Onderdonk Avenues. They allowed him to set up shop on their premises, and he would kick a little something their way for the favor. So on evenings and weekends, my grandfather created his office space with a card table and a folding chair and waited for customers to roll in.

And they did roll in, in fact. There were no shortage of people who needed help with their taxes. Unfortunately, nearly all of them were of extremely humble origin. Cleaning ladies. Shift workers from nearby paper factories and small breweries. A guy who delivered flowers to the enormous number nearby cemeteries. People who made very little, who just wanted one less thing to worry about.

My grandfather found himself unable to ask these people for money. And if they offered, he turned it down. He did not make one cent with his tax experiment. In fact, thanks to his arrangement with the laundromat, it wound up costing him money.

To me, this is the true definition of charity: Not giving what you can afford, but giving what you can’t quite afford to someone who can afford it even less. My grandfather had six kids. He had every right to charge these people, no matter their circumstances. But he decided he could endure a little pain to alleviate someone else’s.

I try to keep this in mind when people ask me for favors that will put me out a little bit, or to contribute when I’m a little bit short on cash or time. I’m not nearly as generous as I should be, and I’m not proud of that. Still, I am grateful to have such an example on which to draw. Because if my grandfather could have given his time and money back then, chances are whatever situation I’m in right now, I can, too.