Funny you brought that up because I just read that same section in the same book last night even though I have had a c-section already.
Yes it is true. It is only because the surgery itself is major. From the point in the back down must be totally absent from sensation because it involves every layer into your body. Like with an epidural, you can still feel pressure and some sensation of contractions, you could not tolerate that with the invasiveness of a c-section. Therefore the medication administered is much stronger and lasts much longer.
It wears off from your toes up and so you have to make sure your body is up for movement. I would also say that because of the nature of the surgery, they want to make sure that all of the layers have adhered to where they are supposed to and stopped bleeding. Trust me, you do not want to move around that soon after. Sleep is GOOOOOODDDDDDDD.
I will be having another c-section on Friday, I plan on taking advantage of the sleep factor as much as possible.
Hope that helps.
Married October 02
DS Caden Grey June 03
DS Morgan Keenan March 05
C-Section Aug 1st 08 with baby BOY #3