....about copy editing is that you are sometimes (oftentimes) amazed at the things you didn't see even though you've read that manuscript 498 times (which, of course, is why you didn't see them).
[From The Short, Sad Life of Tooley Graham]
When he heard the click clack of her heavy black shoes on the wooden stairs, he clamped a hand over his mouth to stifle a giggle. When he heard the kitchen door swing open, he clamped another hand over his mouth, his shoulders shaking with a silent laugh.
The copy editor suggests "his other hand" instead of "another hand."
(She politely points out that he only has two hands.)
Reason #543 why we need fresh eyes on our work.