" Helen, a junior high math teacher in Minnesota, spent most of the school week teaching a difficult “new math” lesson. She could tell her students were frustrated and restless by week’s end. They were becoming rowdy so she told them to put their books away. She then instructed the class to take out clean sheets of paper. She gave each of them this assignment: Write down every one of your classmates’ names on the left, and then, on the right, put down one thing you like about that student.
The tense and rowdy mood subsided and the room quieted when the students went to work. Their moods lifted as they dug into the assignment. There was frequent laughter and giggling. They looked around the room, sharing quips about one another. Helen’s class was a much happier group when the bell signaled the end of the school day.
She took their lists home over the weekend and spent both days off recording what was said about each student on separate sheets of paper so she could pass on all the nice things said about each person without giving away who said what.
The next Monday she handed out the lists she’d made for each student. The room buzzed with excitement and laughter.
“Wow. Thanks! This is the coolest!”
“I didn’t think anyone even noticed me!”
“Someone thinks I’m beautiful?”
Helen had come up with the exercise just to settle down her class, but it ended up giving them a big boost. They grew closer as classmates and more confident as individuals. She could tell they all seemed more relaxed and joyful.
About ten years later, Helen learned that one of her favorite students in that class, a charming boy named Mark, had been killed while serving in Vietnam. She received an invitation to the funeral from Mark’s parents, who included a note saying they wanted to be sure she came to their farmhouse after the services to speak with them.
Helen arrived and the grieving parents took her aside. The father showed her Mark’s billfold and then from it he removed two worn pieces of lined paper that had been taped, folded, and refolded many times over the years. Helen recognized her handwriting on the paper and tears came to her eyes.
Mark’s parents said he’d always carried the list of nice things written by his classmates. “Thank you so much for doing that,” his mother said. “He treasured it, as you can see.”
Still teary-eyed, Helen walked into the kitchen where many of Mark’s former junior high classmates were assembled. They saw that Mark’s parents had his list from that class. One by one, they either produced their own copies from wallets and purses or they confessed to keeping theirs in an album, drawer, diary, or file at home. "

― Joel Osteen , Every Day a Friday: How to Be Happier 7 Days a Week