Jamie-Lynne Knighten spent only a few minutes with Matthew Jackson before his sudden death, but it's a few minutes she'll never forget.
Knighten, originally from Toronto, met Jackson during a stressful grocery shopping trip earlier this month in California.
With a fussy, jet-lagged baby in tow, she was at the checkout line when she realized she'd forgotten her debit card at home. She scrambled for her Canadian credit card.
"Swipe... Decline.. Swipe.. Decline..." she wrote on Facebook. Having forgotten to tell her bank she'd be travelling, they had locked her account. As she tried to call her bank, her phone died.
That's when Jackson spoke up. "May I?" he asked. She was so overwhelmed, he repeated the offer: "May I? May I take care of your groceries?"
A week later she called Jackson's workplace, hoping to send a thank-you gift. That's when she got the tragic news.
"I hear crying on the other end of the line and my heart sinks... I just knew something was wrong," she wrote.
The person on the other end told her that 28-year-old Jackson had been killed in a car crash not long after his good deed.
"I thought for sure I would get the chance to see him again, give him a hug and thank him at least once more in person. Now I won't get that chance, but more importantly no one else will get the chance to meet him. And that breaks my heart."
Knighten shared the story in a Facebook post and now people are taking Jackson's words to heart and looking for ways to pay it forward.
On a Facebook page named for Jackson, total strangers have been leaving stories of small acts of kindness.
One reader sent a message about making sure a senior who left money in an ATM was able to pay her rent. Another reader in the Philippines committed $200 to help feed children living on the street.
According to the Los Angeles Times, the goodwill has even touched Jackson's sister and brother-in-law. While driving to Jackson's memorial service, they stopped with their four young children for a meal. When they asked for the bill, they found out someone had already paid for them.
"There has got to be some good to come of this," Jackson's mother told the LA Times. "He would be happy to know that other people are learning from his example."