[gumby]

To add to the other comments: the work of figuring out how to break things down often requires long periods of quiet thought. In addition, I often refactor as I write, as the process of implementation can uncover poor design decisions made up front.

In short: my work is rarely "beads on a string" that can easily be popped off, and to the degree they are, the unit of time is typically hours, not a half hour.