Breanna Stranger, a college student from Lakewood, eases up to the McDonald’s drive-through window to pay for her Egg McMuffin, only to find the driver ahead has already done so.

Lauren Gresh, 19, gleefully peers through the window of a Yogurtland in Centennial as dawning amazement slides across the face of the businesswoman whose yogurt she secretly bought.

Two young women walk into Linda List’s ice cream shop in Golden and ask what they can do for her. List can’t think of anything. “I’m really good at cleaning bathrooms,” one said. So they do.

Random acts of kindness. Little gifts with unpredictable and, sometimes, limitless reverberations.

“It really brightened my day,” Stranger said.

“That was pretty amazing,” List said.

Here is Gresh’s philosophy: “You want to move mountains, but you can’t. You can only start by pushing pebbles. It’s the little things that will make a difference some day.”

Push enough pebbles of kindness and who knows what might happen.

Take Rachel’s Challenge, a program aimed at creating a culture of kindness and compassion, which grew from the beliefs of Rachel Scott, 17, who died in the 1999 Columbine shootings. Her father, Darrell Scott, and stepmother Sandy started the program after discovering her writings and drawings. “I have this theory,” she had written, “that if people can go out of their way to show compassion, then it will start a chain reaction.”

Today, Rachel’s Challenge reaches 3 million students worldwide and is in 2,000 schools nationally, Scott said. Because of its teachings, school officials report significant reductions of bullying and hundreds of prevented suicides.

“The built-in challenges are there about how we treat each other,” Scott said about the program. “Kindness should be our way of life.”

But, sometimes, for all kinds of reasons, it gets lost.

Stranger, who was grabbing breakfast at McDonald’s that day on her way to Colorado School of Mines, blames technology and social media for erasing the personal connections that humanize us.

“There’s so much social media that we forget how to interact with each other,” she said. “We forget how to treat each other kindly.”

Research is substantiating that sentiment. Sherry Turkle, a technology and society professor at Massachusetts Institute of Technology, argues in her book, “Alone Together,” that we are heading toward greater isolation for precisely those reasons.

A busy world also interferes.

People are often too overwhelmed with their lives to take time to be kind, Denver resident Laurie Liddick said.

But we need to stay connected. And we need to take the time.

Otherwise, as Rachel Scott wrote, “… people will never know how far a little kindness can go.”

Renée Hughes found it went 30 cars.

The college sophomore was working at a Denver-area Starbucks last year. Every day, the same woman would buy the coffee of the driver in the car behind her. The domino effect would continue for five or six cars. One day, it continued for 30.

“My co-worker and I kept track because it was the longest chain we had ever seen,” Hughes says. “It was the most incredible display of kindness. … That kind of thing restores hope in the human race.”

For some, as with Darrell Scott and the women at Linda List’s shop, acts of kindness have come from loss.

At first, List was taken aback by the two young women’s request to help. Then she heard their story. A friend had been murdered several years earlier. So “they did this, once a year on a certain date. … This was their way of remembering that friend and trying to make a positive out of a tragedy.” List kept their card. “I wanted to remember that.”

For Lauren Gresh, a University of Colorado student from Castle Rock, the idea of performing random acts of kindness took root three years ago, when she first heard about Lynda’s Legacy at a youth leadership conference.

A Colorado woman started the organization to honor a promise made to her friend, Lynda Drabek — who died from a terminal pulmonary disease — to continue her practice of secretly performing random acts of kindness.

The idea impressed Gresh, so much so that it has become part of her daily routine. “It kind of gives you a bit of hope and respect for the people around you,” she said. “You can see that there are still good people in the world and people willing to do this kind of thing with no intention of getting something in return.”

On that night at Yogurtland, Gresh had given the cashier a card to give to the businesswoman. It said: “You’ve just received a random act of kindness.” After the bewilderment dissipated, the woman excitedly turned to the teen behind her, who happened to be my 18-year-old daughter, Brooke, and offered to buy her yogurt. Brooke then offered to buy her friend’s yogurt, but the woman insisted on paying for the other five teens in line.

“It was obvious,” Brooke said, “that she was so overcome with emotion that she felt the need to pass it on to us all. … It was pretty powerful. There was so much gratitude. You could see it in her eyes, in her smile, and you knew that that act had made her day.”

As Brooke left Yogurtland, she met Gresh, who gave her a card like the one the cashier had given the woman. Brooke tucked the card into her wallet and carried it with her back to college last month. She’s waiting for the right moment to use it.

The beginning of a chain reaction.

How far, I wonder, will it go?

Ann Macari Healey, who has edited and published weekly newspapers with her husband, Colorado Community Media publisher Jerry Healey, reported for The Miami Herald and The Providence Journal before coming to Colorado. Her column about people, places and issues of everyday life appears every other week. She can be reached at ahealey@ourcoloradonews.com or 303-566-4110.