I wish customers were more specific.
Whenever someone asked for "a cup of ice/water", I assume they're asking for the small white concession cups because those are the water cups we give people that are asking for ice or water for free. Nope, they actually meant the fountain cup that comes in sizes. They can fix their own drinks, but they have to pay for the fountain cups they're asking for which for some reason surprises them.
I also hate when they ask for "popcorn and drink", not the specific sizes, just popcorn and drink. It's a little irritating because the menu is right above me where they can see it and I guess they never really bother checking it. I love my job, but I don't think they know we can't read their minds.