Authors of Tildes: How well do you know your own book when you publish?

I've spoken with some authors who are working on non-fiction books. I've noticed that some of them know their books intimately and can correctly if I mis-relay a section back to them that I've read. They can do this without checking the actual book and I've then verified that I was incorrect.

Others have told me that by the time they were finished a seemingly infinite number of edits, they can't bear to read their own book again and just sent it to an editor at that point and released it.

I was surprised by the latter but it does remind me of my own experience writing very long papers in college. Is this common in your own experience?