I have chronic insomnia and I blame it on all the years I worked night shift (11PM to 7AM or 7PM to 7AM). Am a slug all day but when the sun goes down I come alive and am up til 3 or 4AM. Have tried benedryl, tylenol PM, melantonin and prescription drugs like ambien and trazodone. Nothing has worked. I cannot live like regular people...so, I gave up trying.
I get up when I get up and if I need a mid-day nap so be it.
That having been said, I get along very nicely now with 3 or 4 hrs of sleep at night and a 2-3 hr nap.