"I have a friend who's a single father and has a hard time making ends meet and lives in a little yucky apartment, and he could always use the help to be a better parent to his children," she said.
She's talking about Curt Martin, who has two kids and often cares for her own daughter, Angela, who has autism.
Martin recently saved up for months so he could take the neighborhood kids to Knott's Berry Farm, including two kids with special needs.
We followed Gates to Martin's residence in Los Alamitos. He had no idea what was coming.
"You do so much for everybody, and nothing for yourself. They stopped me, and you immediately came to mind," Gates said to Martin on his doorstep, while choking back tears. "You deserve this money, I want you to have this $500."
Martin appeared speechless. He thanked his friend in an embrace.
Martin had a hard time accepting any credit, though. For him, making the children he cares for happy is worth all the work.
"It's just fun to see the joy on their face and seeing them enjoy something," he said.
Gates said Martin's help dealing with Angela's autism has been life changing for her.
"He doesn't judge my daughter, and he just treats her like she's his child too," gates said.
Martin, of course, wants to use this experience to teach his kids.
"Just keep doing the good work like that, paying it forward," he said. "The world will be a better place if people keep doing that."
Want to Pay It Forward? Tell us who you think deserves $500 on the Pay It Forward tab on our Facebook page. Every week until March 30, 2012, one person will be selected at random to receive $500 to Pay It Forward.