That's an interesting idea to think about: if the thought of not completing a challenge in an expected timeline bothered me so much that I took every step to meet the timeline, and leaving something undone didn't give me a very strong icky feeling, what would I do differently when things inevitably turn out to be more complicated than I originally thought? Turn in my code in a non-working state and say it's done?

In the extreme case, I guess so. The other extreme is the person that will never complete a task as there's always some detail to refine.

But it's a spectrum where most people are somewhere between the extremes.