PM: How long is this going to take you?
Me: No idea, I've never done it before.
PM: Well what's your estimate?
Me: Any estimate would be useless because I've no idea what difficulties I'll encounter.
PM: But I need to put a number on the plan. How about 15 days?
Me: Sure, why not? Let's also estimate I'll grow wings and complete this project while flying.
Me: "Five years"
PM: "Five years?!?! Why is it going to take you that long?"
Me: "It probably won't, but as I already told you, we're going into a territory with an untold number of unknowns, and I don't want to give you any false hopes about an unrealistically short deadline. If you would like me to lie to you, please make that request in an email so I can have a timestamp."
PM: *Leaves, red in the face, so I can get back to work before the next useless interruption.*
