In the midst of our busy lives, it's easy to forget how impactful simple acts of kindness can be. It only takes a few minutes, or a small gesture, though, to pay it forward and show kindness to others. Nineteen-year-old Mackenzie Mauller discovered firsthand how a little kindness goes a long way last week when she bought coffee for a woman at Starbucks. Mackenzie pulled up to the Starbucks drive-thru in Ohio and told Inc. that she just felt like doing something nice. Later that day, she found a note in her mailbox from the woman whose coffee she paid for.In the heartfelt note, Nicole Clawson thanks Mackenzie for buying the coffee, explaining that she and her family have been going through a hard time and that she was feeling so guilty for getting herself a coffee since things had been tight financially for her. She goes on to say that she cried once finding out that Mackenzie bought her coffee and was thrilled to see that the two strangers actually lived in the same neighborhood. "I felt it necessary for you to know that what you did for me was more than just a coffee. It was something that has turned my whole day around, put tears in my eyes and a smile on my face and I feel so grateful. Thank you!" Mackenzie tweeted a photo of the note saying, "Small acts can make a big difference folks, spread kindness."Mackenzie's tweet has more than 80,000 likes and has been retweeted over 20,000 times in a week. Nicole replied to Mackenzie's tweet, noting that Mackenzie thanked Nicole in person for the card and also offered to help babysit her kids. After Mackenzie replied and said, "You're so welcome!!!," Nicole added that her kids are eager to pay it forward, too. People responded on Twitter, sending well-wishes for both Mackenzie and Nicole, and applauding Mackenzie for the kind act. Starbucks even shared Mackenzie's tweet, writing, "Kindness Matters."It certainly does! Check out six amazing stories of kindness by kids in the related video above.