The BRAIN also has the capability to recuperate from from various level of damage over some time , the Brain is very complex and we still don't know much about it . You also forget to realize that the reason a person never acheives that "1st roll feeling" after 10,15,25th roll is because of a condition refered to as HABITUATION ( your body-brain got used to it ) and it isn't a Novelty , it doesn't really have any connection with PERMANENT BRAIN DAMAGE per se . After nearly 4 years of Moderated usage , and in my final year of College w/ Med school in my horizon ......hmmm make your conclusion ,am i really Brain dead ?