Say a simple Hello

I was leaving the grocery store, and an elderly lady was walking in, and I simply said "Hello". She stopped , got closer and indicated she hadn't heard me. I repeated my hello and she said "thankyou, I am here because my husband is very sick and I must get alot of groceries. Thank you so much for saying hello" and on she went. It is really a Christian thing, just to say or do something nice for people. Simply to notice them.