You're supposed to just write. Sit down, type, and turn a white page into black. Not let anything else matter except the story you want to tell. But I can't help but keep track of the meta-data for my writing.
I note the time when I start, and after 30 minutes check to see what my word count is. Another check is made at the hour mark. I typically average ~500 words an hour, so this is where I decide if it's going to be a good day or a bad day. Either way it keeps me pushing forward, and has ensured that I write at least 1,000 words every day for the past three months.
I'm in love with the statistics about my writing. I have an overall spreadsheet to keep track of estimated completion dates for projects, and average weekly word counts. Only 4,000 words this week? That means the first draft of Pillars of Wrath won't be done until November 30. That bumps into my timeline for Tales of a Dying Star, so I'll need to pick up the pace next week, or write a bit longer on ScifiSaturday.
Each individual project gets its own spreadsheet too, with outlines and word counts for each chapter. Pillars of Wrath is 92,024 words. I've completed 21 out of 28 chapters, averaging 4,382 words per chapter (though varying between 2,900 and 7,200). Seven remaining chapters at that average means a final word count of 122,699 before editing. But, the last three chapters I've written have averaged 5,620 words, so I'm starting to stretch out more.
If you could see my spreadsheets you'd swear I was autistic.
I find it comforting to create an order in the madness. All this data doesn't inhibit me (aside from a little wasted time), and even helps me feel a sense of accomplishment with each new update. Instead of several projects in vague states of incompleteness I have measurable progress toward a specific goal. I wrote, the word count incremented, and I'm that much closer.
Only with immense willpower do I avoid doing this with the books I read. I don't note that I read 40 pages of Prey in an hour, and at that pace I'll finish by Thursday, which brings my yearly total to 14 books, but I could bump that up to 19 if I increased my daily reading by 20 minutes!
Nope, I don't do that. That would be really crazy, whereas I'm only mildly crazy. But I think about doing it.