chug and plug away

How is it that I always underestimate the amount of time I need to complete projects and end up scrambling in the end like a crazed insomniac? It's one thing to do it when you're still in school, but now that I'm not, you would have thought I would have learned by now...I've got 6 more pages of the Christmas medley to go before I reach the double bar. I had forgotten how tiresome/time-consuming sequencing/arranging/orchestrating could be...