Bren Batlan is an artist who leaves his work around cities for people to take for free. (He also sells it if you really want to own one of those adorable paintings) Attached to each is a note that reads, “This painting is yours if you promise to smile at random people more often.”

Check out the feedback on his site to see how deeply this simple act can change people’s lives.

One example:

One winter afternoon I was walking through Holyoke Center in Harvard Square after coming from the doctor’s office and realizing that I was going to have to take a leave from my job at the university. I was crying and nothing that my sister seemed to say to me was giving me any solace. As I was walking by one of the benches I saw someone smiling at me. I smiled and kept walking in a daze. As I was about to exit out of the door, I unhitched my arm from my sister and turned around and started walking towards the bench without saying anything to her – something was pulling me back. It was what had made me smile and what had caught my attention from the corner of my eye. It was the green finger-smiling-good mood maker-alien cartoon. There he was sitting on a bench waiting for me. I couldn’t believe it. He had the whole bench to himself and the center was packed with people milling about. Attached to him was the note ‘This painting is yours if you promise to smile at people more often’. I stopped my crying and started laughing. I swear to God that this meeting gave me something that I hadn’t felt in months – lightness and I know this sounds cheezy but hope. It felt like a sign or something. And it broke my darkness. Even my sister was laughing – kind of uncontrollably. It was the best mood maker and as we left with it, it seemed to give us the lift we needed or sent out some sort of vibe to other people around us because we met like 3 awesome dogs that night, a bunch of super nice people, and kind of kept running into random good energy ‘stuff’. I kept it in my bedroom for six months. I’m in a much better place now and felt like it was time for him to work his magic on someone else. My friend just had a baby. They named her Nelly but her real name is Prunella – the poor thing – she needed some magic. So now its in her baby room. And I told her older sister Bernadine (I know, I don’t know why they are obsessed with naming their kids with these names that belong to great-Aunts) who is five now that when she wanted to she could take out the painting – which still has the sign taped to it – and put it in some random place in Jamaica Plain for someone else to pick up. She liked that idea. — Catherine