One of the most powerful and important axioms in software engineering, in my opinion, is "Ya Ain't Gonna Need It". This axiom tells us that we shouldn't be implementing code on pure speculation of customer needs, but rather wait until we have solid evidence of the need from customers. I explore multiple personal stories of this in action, tips for recognizing when speculation might be occurring, discuss language to combat it, and how we can also apply this to some of the code we write.