Ah, Extreme Programming. From one of the Extreme Programming FAQs:
in reply to Re: Design Patterns Considered Harmful
in thread Design Patterns Considered Harmful
What does YAGNI mean?
"You aren't gonna need it," a general refrain when someone suggests building functionality for the system that isn't required by any current user story. For example:
Programmer 1: "It says here we need to save the default number of widgets between sessions. I'd better write a generalized object persistence mechanism."
Programmer 2: "YAGNI. Just write out a one-line text file for now. If we need more later, we'll add it later."
Hey patterns are cool. But most often, YAGNI.