“I think that light is flickering,” Clara said tiredly. I looked up from my burrito and squinted across the restaurant. “Oh. Yes, it is. See,” I pointed, “Look at the wall next to it.” As the light flickered, the white wall seemed to blink randomly. The kids all turned to watch. It strobed black and white erratically and I started to feel a bit queazy. “Okay okay.” I closed my eyes and turned away. “Let’s not do that. Staring at a wall like that will give you a headache.” Two out of the three of them went back to their dinner, but Lydia remained with her gaze fixed on the distant wall. “Yay!” she cheered quietly to herself, “I have never felt a headache…