Welcome to Idiomatic Expressions 101, where we're learning to be unhelpfully precise with our words.
It's a classic. You know the one: "I'll just have one more bite of this cookie." No, you won't. Don't do that.
Underbites: A Study in Self-Deception
This one's a real doozy: "It's not a bug, it's a feature." Yeah, right. That's why you just spilled coffee on your shirt.
Feature Bugs: Because Who Needs Functionality, Anyway?
You know: "I'm not a doctor, but I play one on TV." Nope, you're not a doctor. You're just some guy on TV. Don't pretend otherwise.