Somewhere in the 2-to-4-year range, kids tend to ask "why?" a lot.
This probably gets frustrating at some point for parents, but it's an important part of a child's development as they grow curious of their surroundings. At some point in our lives though we lose this natural curiosity. We lose the desire to discover "why".
It's a shame, really. We learn so much by asking questions. "Why" demonstrates a desire to understand, to demystify the unknown.
As a child, our questions tend to be centered around our surroundings, but as adults we can pivot this into self-reflection. Toyota codified this in The Toyota Way, Toyota's principles for building a stronger business. In Principle 14, Toyota aimed to "become a learning organization through relentless reflection".
Part of this comes from determining the root cause. Asking why.
To help get to the root cause of an issue, ask "why" five times (or as many times as is required to find the root cause)
Our application crashed and was down for customers for 6 hours.
Why did it go down? A defect in the code caused the system to run out of memory.
Why did it run out of memory? The code was not designed to handle the number of users.
Why was it not designed to handle the number of users online at that time? When the code was built, the target market was significantly smaller than it is now.
Why did we not evaluate the application for the extra load we've taken on over the years? Because we lack the resources required to do that evaluation.
Why do we lack the resources to do that evaluation? Good question!
By continuously asking why, we start digging into a root cause that can help address the root cause of an issue.
If we simply addressed the initial issue – the symptom, not the cause – we wouldn't have taken the time to think about the team not being able to proactively address other performance bottlenecks that could impact the application.