How Often Do You Revise Your WIP?

Funny how random things are.

I was formatting a booklet of one of my Mall Demons chapters for my students. I was having problems formatting the pages. I ended up having a space in the text box needing to be filled. It was a paragraph-sized hole. In other words, an extra paragraph of dialogue, narration, something would make the document ready for printing.

So... I added a paragraph. But after printing, I couldn't stop there. I scrutinized the chapter, grabbed my favorite red pen and began marking up the print out.

I was still adding red marks on my 45-minute subway ride home. On the couch - once I'd changed into comfy night clothes - I pulled out a clipboard, and marked some more. 

I put the chapter down because I had to ask myself, "Was I changing it needlessly?"

I don't have an answer, but I wonder if anyone can relate?