Well somebody obviously woke up on the wrong side of the bed that morning. You should have responded out loud "You don't want to have a nice day, sir?" People hopefully would have clued in that old man was just grumpy.

He was having a perfectly miserable day until OP came along. For shame!

Or! "Some kind of Monster" yeah!!

How DARE you wish somebody a nice day.

I would have responded back" ok dont have a nice day if that makes you feel less grumpy"

It's a virtuous thing to do...but as many people may say don't tell me how to live my life or tell me what to do...that shouldn't happen too often though...don't take it personally..,

This is why old people dont deserve senior discounts..

It's k some people just don't like good service or politeness

Maybe people were looking at him like he was an exhibit.

Old people. They're everywhere. That's why you always have to be prepared with an old person emergency kit. I never leave home without it.