Again, this is one of those things that apply to some and not others. I have been a chronic insomniac for over forty years and always feel envious of those who can indulge in 'nana naps'. If I don't take a sleeping pill, I just don't go to sleep. It has huge advantages when travelling because I don't suffer jet lag. But I have just undertaken a series of cognitive tests and have no problems. (YET!!!!!!!!!)Interesting my husband also worked shifts, didn't get much sleep and has early onset dementia. I have just finished a book on sleep which spoke about the different stages of sleep and the risks of lack of sleep