Sleep is a good thing

Having been woken every. twenty. minutes. last night, I'm a little obsessed with sleep. And the lack thereof. And...because I haven't slept...my mind's doing weird and wonderful things. Like so:

• Do you write when you're tired? I don't just mean 'sleepy', I mean..barely able to keep my eyes open tired.
• Do you read when you're that tired?
• Do you prefer to read/write in the morning, or late at night? (and are you a Morning Person?)
• How often do you read about people sleeping in books, unless they're a) attacked by bad guys or b) have a prophetic kind of dream?

And the question I really want to know...

Have you ever read a book where the main character has been deprived of sleep for so long that they simply can't think properly? And if so...what book is it?

Because I've got to say, I haven't slept since Thursday night. Not properly, anyway. And it makes me punchy. (It also makes me try to pour my kettle into my toaster while making breakfast, too.) And I'd love to read a writer who can capture that whole feeling.

And now...it's time for either more caffeine...or a nap...