Cristoforo Colombo (a.k.a Columbus) knew how to sail, navigate, sell a proposal. He was commissioned to find a new route to India. He didn’t find India. Fortunately for him and his career, he found something even more lucrative.
You’ve got skills, right? Coding skills, architectural skills, fried skills, skills gumbo, nun-chuck skills… But if you’re commissioned to write a piece of software that takes your stakeholders to India, how will they feel when they wind up somewhere in the Caribbean? You could pull a Columbus and try to convince yourself and everyone else that they really are in India:
You: “But this is India, I tell you! See? Look at those Indians. You there! Yes you, Indian! Come hither at once!” Stakeholder: Raises a doubtful eyebrow. Takes a long, exasperated breath. “Indian”: “Oye papi. ¿Sabe? Tu ta loco.”
The point is: you know how to code, but are you coding the right thing? How do you know? That’s where Specification by Example comes in.