Friendly gestures

Is it sad to blog about something nice and friendly? Is it so unusual already that I thought it was nice?

I went to MPH last week, and when I had paid and slowly moved away, the girl at the cashier called me back. I was so entrenched in my thoughts that I didn't hear her, or react to anything, until a younger guy in the queue actually called on me, and stopped me. What happened? I forgot my change. I had paid with RM100, and forgot to pocket my change. So I walked back and collected it, and, going back again, thanked the younger guy.

He grinned and said, "is okay and have a nice evening". I do the same, sometimes, but it blew me away that someone can actually be that friendly. Is this normal? Am I unnormal to always see the things that don't work so nicely? I know this is a boring entry, but I thought it is worthwhile.