Embarking on a task, realizing that it requires more foundational work than I'd anticipated, and plowing ahead regardless in an attempt to finish it all in one

Embarking on a task, realizing that it requires more foundational work than I'd anticipated, and plowing ahead regardless in an attempt to finish it all in one go. It nearly always leads to frustration and lousy code. Then I have to back off and break it down properly into manageable chunks.