Young man paid a stranger’s grocery bill and asked in return that she help someone else: one day later, he died

Jamie-Lynne Knighten, 29, was standing in line at a Trader Joe’s in Carlsbad, California, holding her crying 5-month-old baby. Her card was declined. Behind her, the line grew, and so did her embarrassment.

That’s when Matthew Jackson appeared, 28, a personal trainer at a gym in Oceanside. Without knowing her, he paid the $200 for her groceries. When she wanted to thank him, he asked only one thing: that she do the same for someone else someday.

The next day, November 11, 2015, Matthew died in a car accident in Oceanside. Jamie-Lynne found out a week later, when she called the gym to thank him.

That gesture at the supermarket checkout was one of the last things he did in his life, and today it continues to be repeated every time someone decides to pay it forward.