As an (exaggerated) example, the conversation usually goes like this:
Project Manager: Guys, we just landed a huge project from Acme Inc. Guess what, you guys are gonna be paid a bonus this month!! YAY!
Developer: Great!
PM: There's a tiny caveat though: The bonus was promised only if we had delivered it yesterday.
D: FML.
PM: But don't worry, we still have a week to finish it!
D: WTF? But this will take at least three weeks!
PM: Ah, don't worry. I know you can do it in one week. In fact, I am so sure, I promised them you would! Isn't that great?
D: Well, what if I can't?
PM: Oh well, we won't get paid and it will certainly reflect in your appraisal and you won't get that promotion that you have been due for the last three years. But I'm sure you won't let that happen, amirite?
D: FML.