After 2 years of all of those customers thinking that they know how to do my job better than I do, this is very satisfying.

(Five minutes before this conversation, we ran out of iced grande/venti flat lids, so we had to give out dome lids instead. No joke every customer who got an iced grande/venti drink had asked for a flat lid instead of the one I gave them. I had been nice and smiled saying that I was sorry to inconvenience them SO MUCH by giving them a dome lid. After the 245924th customer asking for a "normal" lid I was pretty sick of explaining that we didn't have flat lids to fit their drink... and that the iced tall lids they're pointing at wouldn't fit either.)
147xxxx: Alright, here's your iced grande iced coffee
Customer: Uhmm... Can I have a flat top?
147xxxx: ... I would have given you one but we ran out. We only have iced grande/venti dome lids.
Customer: Oh... (looks at the stack of iced tall flat lids, frowns, and then looks at me) You ran out? what's that?
147xxxx: This? ...THIS is an iced tall lid. It won't fit, but here you can have this lid as well.
Customer: oh... sorry to have questioned you.
"SORRY TO HAVE QUESTIONED YOU" brilliant.