There's a Reason I know I Had 18 Items In My Basket

I was at the local grocery establishment yesterday, I only shop for myself so I usually carry around a basket instead of going full cart. At the store they have these self check-out lanes that people can use. I was in line, waiting for my turn, and this lady in back of me starts complaining to me.

“These lines are express lanes, you can’t have 30 items in these lines.”
“Really?” I say, “because there’s no sign that says they're express lanes. Look at that isle right there, it has a sign for express in big lights. And besides, I only have 18 items.”

Fuck you lady.