Sometimes when I'm having a blah day, I look for a way to brighten up someone else's day. And that brightens my day too.
Last week I stopped for gas and when I went in to pre pay (I'm so old, I don't pay at the pump), a young lady who worked there was collecting the trash out of the bins. She was trying to pull the bag out of the bin, but it was fighting her all the way. I stopped and held the bin down, and together we rocked it a bit, and she got the bag out without it ripping open.
When I left, she saw me, waved, a big smile on her face.
What did that cost me? Nothing. 10 seconds. We both got a smile out of it.