There are some moments you'd rather sleep through, pass from point A to point B without awareness of the time passing or the events that carry you from present to future. And it's mostly those moments in which it's smarter-safer- to stay awake.
There was a certain history to this. While heavily pregnant with Amelia, she had asked him if she was radiant or if she just looked like a waddling duck. He told her she’d looked like a radiant duck. This had not been the correct answer.