It's a very simple question. For most folks.
The answer for most people is... when they get tired and/or sleepy... duh!
I wish it were that easy for me.
Sleep is an elusive thing for me. Without the aid of a handful of vitamin supplements, multi-vitamin, calcium, l-tryptophan, black cohosh (subject for a whole nuther blog) and melatonin... I'm not sure I could go to sleep after a normal day's activities. I probably could if someone hitched a plow to me and forced me to plow the lower 50.
The thing is, I can be physically exhausted, but if central control is still online, I'm screwed. And more often than not, it's always online. If by chance I am able to sleep but get up in the middle of the night to pee and the husband is awake as well, he's not allowed to talk to me. If he speaks, and I answer, everything boots up, and I'm toast.
So here I am, laying in bed, physically tired, took my supplements, I've caught up on all my favorite websites, checked emails, blogs, etc. but I keep surfing. All because my brain is wanting some sort of stimulation. Kind of jacked up.