I just wanted to let you guys know that I have followed suit and left muffins along with a smile card in our lunchroom at work. It was so hilarious to see co-workers trying to find out who left them.
One just passed by my cubicle saying loudly to everyone in the room, "Thank you whoever left the muffins. They taste great." She had a big grin on her face. It made me feel happy seeing her so happy. I really hope they pass the joy along. Thank you to the original Mystery Muffin Giver for your wonderful story, which motivated me to pass a little happiness around. Giving certainly is fun!