With all due respect -- that is just how some of us work internally. We learn by experimentation, intuition and repetition.

I often find it extremely difficult to write a design document for a system, particularly a system owned by somebody else. I have written design documents in the past, and they rarely end up describing the eventual system, no matter how hard I work to maintain and update them.

In my experience, software design and engineering is an iterative process, like gradually groping in the dark to determine the shape of a room. I cannot simply turn on the lights and take a photograph of the room at the start of the project.

Having said that, I completely agree that in principle it is great to start new projects with a complete design document, at least a functional specification. Accurate technical specifications are a rare, elusive beast, though.