Sometimes the biggest acts of generosity start with the smallest gestures. For MacKenzie Scott, whose philanthropic giving has reached eye-watering heights, it all traces back to a $1,000 loan from a college roommate.

The Moment That Changed Everything

During her sophomore year, Scott found herself in financial trouble, facing the possibility of dropping out. That's when her roommate, Jeannie Ringo Tarkenton, stepped in with a $1,000 loan that kept Scott's education on track.

Fast forward to today, and Scott, who received a substantial stake in Amazon (AMZN) following her divorce from founder Jeff Bezos, has become one of the most prolific philanthropists of our time. Through Yield Giving, her philanthropic initiative established in 2022, she's donated an impressive $19.25 billion to various causes.

But that college loan clearly stuck with her. In one of her essays, Scott reflected on how that moment shaped everything that came after: "It is these ripple effects that make imagining the power of any of our own acts of kindness impossible. Whose generosity did I think of every time I made every one of the thousands of gifts I've been able to give?"

She continued: "It was the college roommate who found me crying, and acted on her urge to loan me a thousand dollars to keep me from having to drop out in my sophomore year."

The Ripple Effect Continues

Here's where the story gets even better. Tarkenton didn't stop with that one act of kindness. Inspired by her experience helping Scott, she founded Funding U, a company that provides low-interest loans specifically to students from low-income backgrounds. The firm has since distributed $80 million in loans to nearly 8,000 students.

Despite the scale of her impact, Tarkenton remains humble about it, crediting the success to the students' own perseverance and hard work. She believes that small acts of kindness can collectively create significant impact, a philosophy clearly reflected in Scott's massive philanthropic efforts.

One thousand dollars. That's all it took to plant the seed for billions in charitable giving and help thousands of students stay in school. Not a bad return on kindness.