“Okay,” Emma said, thinking carefully. “So this is a bit different, but maybe not. It’s sort of the opposite to being bored.”

Izzy nodded.

“It’s just something I thought about once, and then started noticing all the time.”

“Okay,” Izzy said. “Go on.” She seemed to be waiting.

“Not all the time,” Emma said, correcting herself. “But sometimes. Occasionally.”

“So what is it?”

“I don’t know if it makes any sense or not.”

“So tell me what it is. And then I can tell you.”