Oh, I don't know. I find all books to have extremes in them. I think the average person does very well on eight hours of sleep a night. I know I will sleep over seven when allowed to sleep unbothered by DH, an alarm, phone, etc. Others require a lot more, some less. I like their basic premise. You use their book to suit your own needs and life and take it from there. I know my sleeping has improved by reading and applying a lot of their suggestions. I like that book..... Oliva ----- Original Message ----- >And that pinpoints one of the problems I have with the >LIGHTS OUT book: sometimes I think their basic premises are >a bit shaky. They say we should be going to sleep at >sundown, and only the advent of fire is what has made us >change this. I agree with you, it does seem a bit far-fetched, considering our adventurous nature.