Hello ladies and gentlemen. Interesting to see dialogue on sleep deprivation, especially first hand experience with some of its adverse effects. Keep in mind, going 3 plus days without any sleep at all is something that should not be done...and most people have not accomplished this in their lifetime. I, am a trauma surgeon, and get very few hours of sleep sometimes. Sometimes ill do surgery for 14 hours straight on and off, sleeping 4 hours in between. As a competitive student in the pre-medical program at the Univ. I attended, students would often be overwhelmed with stressful situations preparing for exams. They pull all nighters as they call them, and still perform relatively up to par on exams (i have scored A's on very difficult exams in the sciences while very sleep deprived)...no it does not cause sufficient permanent brain damage because if this were the case, many professionals would be retarded, including myself. Donald Trump (if I may quote him) stated that he slept on average 4 hours a night he loves working so much...and his job at times is very stressful...especially in the past before he had stable millions (real estate crash in the 90's). However, one is more prone to deleterious infection upon lowering immune system function by not getting sufficient sleep. All in all, it isnt a monster to not sleep much...sleeping will make you more clear headed though and memory may be better during days following a good nights rest.