Older but Wiser?

I was at the grocery store today, just getting some milk and eggs. The checkout line was super long, so I decide to take my stuff back to the cart and wait. But then, there's this young lady trying to load her groceries into a tiny bag, taking forever. Without thinking, I say 'Let me help you with that.' She looks annoyed but lets me put things in another bag. Then she scowls at me and says 'That’s none of your business, sir.' Oh well, tried to be helpful. If it helps any, I laughed about it on the way home.