enough the toxic waste generated in the brain doesn't get cleared away as it should be and that build up can be conducive to diseases like dementia and parkinson's. and even without brain disease being tired out can make you forgetful. the brain desperately needs a good night's sleep in order to process and file the day's input in significant information is discarded or should be at least important stuff is transferred to the long term memory and stored. the memory is restocked what we can do while asleep is learned via some magical mosis but one giving some rest we do consolidate what we learned during the day. if someone comes to you with sleep problems how do you find the calls i take my time to talk to the people and find out their history what drugs are they taking