A couple of days ago, I squeezed into a seat on the subway, next to a petite older woman who looked annoyed. She looked even more annoyed when I pulled out a pen and started writing in my notebook. I tried to keep my elbows as close to my body possible, but I couldn’t help nudging her a little bit. She leaned into me, and I thought, “Okay, she’s going to complain now.” Instead, she said, “Great hair!”

I smiled and said “Thank you,” but I was smiling even bigger on the inside at these two lessons:

1. You never know what someone else is thinking.

2. If you have something nice to say, say it.

Sometimes I’ve complimented strangers and wondered if they thought I was crazy, but what does it matter? My subway neighbor really brightened my day and toppled the chip I was perching on my shoulder. When in doubt, lean in favor of adding something positive to the world.