Client: "The app moves slowly and has moments when it freezes! Why?"
Me: "Let me check the server...it has 5 GB of memory allocated for it and you are making it load 4.76 GB and never cleaned the log files..."
Client: "Then it should work fine! Almost 500 mb free, it`s a lot! Let the log files be there, we might need them in 5 years!"
Me: "What?..."

It`s better to have an error than to have your app run but not working as wanted. Like in games, you know you`re on the right path if enemies show up, like the errors here.

Having an english conversation with a russian client.
"What do you want the info to be?"
"I want the name, adress and etc."
"Etc?"
"Yes! I attached you a picture with everything...as you can see..."
<the picture is a huge table in russian>
"But the table is in russian"
"Yes"