In Part 2 of Why We Sleep, Walker describes how insufficient sleep proves ruinous to critical brain and body functions. Which of these is most concerning in your view? Why?

Do you believe you are getting enough sleep? How do you know if you are getting enough sleep? Would Walker agree with your self-assessment? 

Are dreams by-products of REM-sleep? How does the brain generate dreams? What are the functions of dreams? Do you think it is fair to judge an individual based on what they are dreaming about, even though they are not consciously creating their dreams?