A friend was talking about the issue of light in the bedroom. She can sleep with it on. Her husband cannot. Which results in her not being fully clothed when she gets up in the dark before him to help kids get ready for school. She is still in her pajamas when the rest of the world is dressed for success. Or at least the bus.

Two of her children share a room and also have different tolerance levels for brightness. It does seem inevitable that any pair of drowsy people will have varying responses to illumination. Certainly John and I do. Add to that the possibility that they retire and wake at different times, and in the absence of head lamps need to flick the switch. Or wish they dared. 

One of the things my friend mentioned to her daughters was the invitation to have empathy. 

"It is not hard for you to sleep with the light on. Can you understand that it is for your sister?" 

Years ago when I was still reading books about parenting there was mention of the tendency for some kids to be sensitive to clothing. New tags can drive them bonkers. Scratchy seams make them irritable. I had a few kids who found their most comfortable outfits and stuck with them. One son suggested I throw the rest of his wardrobe away. Benjamin has a favorite pair of socks, which admittedly are pretty cool in that they have moose prints on them. I have to remind him to take them off and wash them, or he will wear them for ten days straight. 

In the absence of an impartial device to measure individual visceral responses, some things have to be simply believed.