> Who hasn't come up wit the most perfect elegant design, only to come up against three reality of implement and an "oh we forgot about that" aspect

The mistake here is trying to come up with the most elegant design. You solve for what’s needed with the knowledge that you’ve most likely not captured the full situation, and make allowance for future changes.

I don’t want faster code. What I want is flexibility in evolving my design and there’s plenty of good tools and practices for that. From ensuring your code is testable to ensuring there are easy ways to experiment with parts of it.

I’ve never been in a situation that says “We’ve not think of that, we need to get back to the drawing board”, It’s been mostly “We need a new version of this module to support this feature”