I had an incident recently......

Yesterday,I was walking into a store ,and a woman opened a door for me.I have good manners,and usually offer thanks when someone does that for me.But that day my mind was occupied and I said nothing.The woman scarcastically blurted out "THANK YOU."I know that I was technically wrong not to thank her,but I didn't care for her arrogance and smarmy attitude.So I smiled and replied :"You're welcome -but don't expect me to make a regular habit out of it!"