Don't Tell Me You Haven't

So, if you sit down to write ten pages and reach a certain point, and write all morning, and produce two pages, which don't contain anything you intended to go onto the ten pages and wind up somewhere else entirely, does it still count as an accomplishment?

Yes.

Because what's the alternative? Beating yourself up about it? That's no good!

Nobody cares how uneven the process was when holding the finished product in their hands. However you get to the finished product, that's the right way to work.