![Hi hi hi ;))](./images/smilies/71.gif)
Perhaps this is because of a tactic I picked up on the NaNo forum during one of the November events: if you get bogged down with a certain scene but know what comes next, just insert a placeholder for that scene and press on. You can always come back later and fill in the missing details.
This has been really handy during the fury of November writing, and all of my NaNo stories (except for the 2013 version which I abandoned early on for other reasons) have the endings I envisioned when I started - but it's harder than I thought to go back and fill in those missing pieces. I just need to be more disciplined, I guess.