I was a child insomniac
When I was young, I couldn't sleep well at all. In fact, I never truly got over my insomnia until I went off to college at age 21 and got so tired from classes and actually socializing at will for the first time, that I not only could sleep, but also developed the ability to take afternoon naps, albeit surreal, timeless naps that never quite involved fully falling asleep.
But when I was much younger, I didn't have the self-control I needed to deal with my insomnia on my own, and after I would be put to bed I would often get up again after five minutes of wakefulness and walk forlornly down to the end of the hall, where my mother would see me, sigh, and put me back to bed. This might happen 5 or 6 times in a night.
So it is with a certain degree of sympathy, but mainly with bitterness, that I remember the night my mother had enough and snapped. She forced me into my bedroom and locked the door! I tried to leave the room but she had secured it from the outside! This was supremely terrifying to me, locked in a dark room (I didn't think to turn on the light, I was so scared), and I was crying and screaming incoherently for quite a while.
Eventually I ran out of steam and got in bed. I don't remember what happened after that. When I think back on it I find it easy to imagine that my hair might have turned completely white, knowing I was that scared -- that my own mother turned on me and imprisoned me because she was angry.
This still pisses me off.