It's ridiculously common, unfortunately.
Consider this common scenario:
You go into a store and buy something that costs, after sales tax, $0.87. You dig into your pocket and hand the cashier four quarters, and two pennies. You're happy because you just got rid of six coins, including those pesky pennies, and in return you'll get just two coins (a dime and a nickel) in change.
But the cashier does a triple-take:
1. You handed over way too much money. You must be an idiot.
2. Not only did you offer too much (the four quarters), but you compounded your silly mistake by adding the pennies. You must be a complete idiot.
3. Wait a minute, there might be a neat solution to this, but it's way too complicated. Why couldn't this idiot customer just give me a dollar bill and let the computer tell me how much change to give? Now I have to enter all this detail and hope I don't screw it up.
Since I'm one of those dinosaurs who not only carry change in my pockets but actually uses it like this, I see this situation at least weekly.