A positive outlook is common among all of the short-sleepers that Fu has studied. “Anecdotally,” she says, “they are all very energetic, very optimistic. It’s very common for them to feel like they want to cram as much into life as they can, but we’re not sure how or whether this is related to their mutations.”

Ross would seem to fit that mould. “I always feel great when I wake up,” she says. She has been living on four to five hours sleep every day for as long as she can remember.

“Those hours in the morning – around five o’clock – are just fabulous. It’s so peaceful and quiet and you can get so much done. I wish more shops were open at that time, but I can shop online, or I can read – oh there’s so much to read in this world! Or I can go out and exercise before anyone else is up, or talk to people in other time zones.”

Her short sleeping patterns allowed her to complete university in two and a half years, as well as affording her time to learn lots of new skills.