I recently learned a lesson the hard way and maybe you can relate.

Over Christmas, I was working on a project with a specific deadline.  I underestimated the amount of time I needed to complete it and so I was behind right off the bat. 

No worries I said to myself, you can pull all-nighters and get it done.  So, I went to work and fully immersed myself in my tasks.  I became tunnel-visioned and could think of nothing else but my project.