While most people don’t function well after an extended stretch of four or fewer hours of sleep a night, there may be a very small percentage who can thrive under these circumstances. In a landmark 2009 study, researchers discovered a genetic mutation in a mother and daughter who seemed to need much less sleep than the average person — the first time any mutation relating to sleep duration had been found (while the sample size wasn’t huge, the effect was replicated in mouse and fruit fly studies). A more recent study, by researchers at the University of Pennsylvania, revealed a variation in that gene, and other researchers are currently observing the sleep patterns of research participants who claim to function on very little sleep.

Nobody knows exactly how many true “short sleepers” exist, but estimates put it at one percent of the population. They wake refreshed and energized after just a few hours of sleep, and those who have been studied tend to pack their lives with tasks that they perform well unaided by stimulants or other crutches. For instance, the very productive Thomas Edison may have been a short sleeper. “Cells don’t sleep,” he said in his most quoted anti-sleep rant. “Fish swim in the water all night. Even a horse doesn’t sleep. A man doesn’t need any sleep.”

Recently, Science of Us spoke with Jenn Schwaner, a 43-year-old short-sleeper from New Port Richie, Florida.

How much sleep do you usually get each night?

On average, I get about three or four hours, and I never feel tired.

Have you always needed so little sleep? What about when you were younger?

When I was a little girl, I’d wake with my father at 5 a.m. I can remember getting up with him that early from when I was about 3 years old. He worked as a computer programmer at Fort Hamilton. On average, we’d get about four hours sleep a night, but we didn’t know that there might be a medical reason for why we didn’t seem to need much.

When we were up, we had to be quiet, because we had a very small house and we didn’t want to wake the rest of the family. My dad would go on the computer or we would watch TV together: old movies like Laurel and Hardy, The Three Stooges, or Shirley Temple. He moved to Florida when I was around 7, but when I was older I had a computer, so I taught myself programming.

Did your lack of sleep impact your performance at school?

I went to a private Catholic school and I was always a very quick, sharp student. But I was also very bored in school, and looking back, I should have pursued so many other things but instead I studied to become a court reporter. I was so bored that I wasn’t looking forward to another four or six years of study. My mother told me about court reporting, which you can do at your own pace.

What did you do when you finished that course?

I got married the very next day — I was only 20. I had my first child when I was 26. Then I had a son in 2000 and another daughter in 2006.

What was pregnancy and nursing like for you? Did you get tired then?

Not really. In fact, with my third child, I didn’t find out I was pregnant until I was 20 weeks in. I wasn’t trying and I was very busy. I was coaching sports, sitting on community boards, and I was president of PTA. I couldn’t even remember when I last had a period, I was running around and doing so many things like a chicken without a head.

But I always said I was made to have children. It never bothered me when I got up in the middle of the night. It didn’t matter if it was every two or three hours, and I nursed all my kids. And then I started taking in foster children. A lot of the babies were born addicted to drugs — meth or prescription meds — and they need somebody to cuddle them and hold them in the middle of the night when they are going through withdrawal. I felt like I didn’t sleep at night anyway, and I knew that these kids really needed someone who wouldn’t get frustrated being up with them all night.

When I had my first baby, my husband was working nights, so he’d sleep during the day. I couldn’t make noise in the bedroom, so I was up doing all the things I normally did during the day while I was also nursing the baby at night. I breastfed her for 18 months. It was just the way it was. It never bothered me.

Was it just the fact that you didn’t need sleep that drew you to foster care?

I worked as a court reporter in dependency court for 23 years. One of my first jobs was in a very small town where everyone in the court system knew each other. I remember one Friday afternoon a 4-year-old kid came in — he had just been taken away from his parents and there was no place for him to go. They were arguing about where he should go. It totally sickened me. Here we were fighting over where a child needs to lay down for the weekend.

So that was my first experience of it, but I didn’t start taking in kids for long-term care until my kids were a older. I’d been hosting foreign-exchange students and I didn’t feel like that was a help. They were all so privileged and I wanted to do something for kids that needed it. And also, it’s not that my parents were hippies, but I was kind of a Peace Corps “I want to make the world better” person.

What’s it like sharing a bed with you? Do you bother your husband in the night?

I was married 22 years, but we are now divorced. My sleeping was an issue for him. He was a very light sleeper, so I slept on the couch for a number of years, probably for about the last eight years of our marriage. It definitely put a strain on our relationship, because he’s the type of person who has to sleep either eight or nine hours a night, and if I walk into the room at one in the morning, I would wake him up and he couldn’t go back to sleep. It caused issues.

You know, when I got divorced, it was kind of a relief. It was like, “Oh my gosh, I can walk around my house without waking anyone.” We had a one-story house for the majority of our marriage. I would think nothing of vacuuming at 2 a.m. and of course that would wake everybody, but now I didn’t have to worry about that. And I have a two-story house so everybody is asleep upstairs and I can vacuum all I want downstairs.

Are you single at the moment?

I have a boyfriend who understands it, and he’s not a light sleeper, so we can share a bed without a problem. There are some nights when he turns around and is like, “You have not slept all night.” And I’m like, “I know. I’m sorry.” He asks, “How do you function?” And I say: “it’s just the way I am. It doesn’t bother me.”

Can you talk me through a typical day from the minute you wake up to when you go to bed?

It really depends on which children I have at my house. At the moment, I have my kids plus three foster kids — a 13-year-old, a 2-year-old, and a 17-month-old. So the babies sleep through the night. I don’t use an alarm clock. I generally get up between 3 and 4 a.m. and I will start to do some work or laundry or cleaning and then I’m usually taking kids to the bus stop starting at 6:30 in the morning. Then I come back and wake up the others who get ready for school for 7 a.m., and then I start the rounds of dropping them off at different bus stops.

I drop the babies off at child care at about 8:30 and I start court calendar at 8:30 or 9 a.m. and I work until between 3 p.m. and 5 p.m. Then I start picking kids up again. The babies first, usually at about 3 p.m.; my 8-year-old gets off the bus at 4 p.m. and then the other kids usually get home between 4 and 5 p.m.

It’s softball season right now, so it’s crazy. We go five days a week at about 6 p.m. One of my morning rituals is cooking dinner. I’ll crock pot so everybody can grab something to eat before their evening activities. And we do homework in the car, then we come back home and the kids shower. If you walk into my hallway, there’s charts everywhere: the rules of the house, who gets showers at what time (to avoid any bathroom collisions).

My oldest is in by 11 p.m.; on the weekends, she’s in by midnight, but that doesn’t mean she shuts down because her friends come to our house and they stay up until about 2 a.m., and they sleep through to 10 a.m. The babies and little kids are asleep by 9 p.m. and the older kids are asleep by 11 p.m.

I don’t worry about my oldest too much anymore, but she can still keep me up. Her curfew is midnight and because I sleep when I’m tired — I don’t fight sleeping — I might sleep from eleven until two. If she’s not home yet, I have to wait for her. My house has always been the hang-out house. I am a big cook and she has a very large room with a fridge and a couch in there, which is the hang-out room for all her friends.

But I usually go to sleep close to 12 and then start all over again. It’s crazy. My life is extremely hectic.

Do you ever feel tired?

If anything gets me tired, it’s stress, and it’s more that I get stressed than tired.

Can you describe what that feels like?

You know, I think as I’m getting older — I’m 43, so I feel it more in my muscles, but my mind still doesn’t shut down. I’ll sit at the computer for an hour. I’ll do a load of laundry. Then I’ll go back to the computer for 45 minutes. And I’ll start making dinner and then go back to the computer and start doing something else. I’m not a very sedentary person. There’s always something to do: laundry, dinner, clothes in the dryer. It never ends.

How did you learn that you are a short sleeper?

I only found out I was a short sleeper about a year and a half ago. My father was working at FSU and he had heard of a study that was being led by a geneticist at the University of Califonira, San Francisco, so he contacted them. When the media heard about it, he was interviewed and he said, “Well, if anyone has this worse than me it’s my daughter.” So ABC came and followed me for 24 hours. My father was characterized by researchers as having features in common with other short sleepers. They think it’s caused by a variation in a gene, but they don’t know a whole lot about it — for example, if it’s more likely to be passed on from men to their daughters or if we even carry it.

Do you think any of your children are short sleepers?

I don’t think so, but if there is a candidate, it might be my youngest … She’s nothing like I was at her age, but she does come through to my room all the time in the night. She’s a light sleeper. She could fall asleep in a wheelbarrow and then be awake after 15 minutes.

When I found out that “short sleepers” were a real thing, it relieved me. I wish that I had looked at it the way the reporters saw it. They thought it was so great, that I was so lucky because I had so much more time in my life to accomplish things. Even though I always had an instinct to fill that time, I didn’t really cherish it and I should have from a much younger age. I fought it for so many years. I would lie in bed and tell myself go to sleep, go to sleep. Shut down! I did everything possible with the exception of medication. I tried meditating and nothing did it. I’ve embraced it a lot more seeing how jealous other people are of me. I have overfilled my life with things, but it’s what I enjoy doing.

You work as a court reporter. I bet that requires a lot of concentration and attention to detail?

It does. I mostly do high-profile criminal cases — first degree felonies. I do death-penalty cases and I have to write real-time, verbatim reporting of everything everyone is saying in the court room. We do it on a steno machine. You can only touch ten keys at a time and you make a language based on phonetics. I’m certified at 235 WPM on the steno machine.

Given that your job deals with such heavy subject matter, do you find it hard to switch off from that? Do you think about the court in the middle of the night?

Very rarely now do I dwell on my work. But when I was young, I would come home and I would be really bothered by the divorce cases. It was terribly hard to see people who had once loved each other treat each other so horribly. I used to joke to my husband, “Don’t ever try to divorce me because I will take my chances in criminal court before I take my chances in divorce court.” We had a very amicable divorce since I didn’t want to do anything that would hurt my kids. But very rarely did the criminal cases bother me.

What happens when you’re sick. Do you find it hard to take to your bed?

Yes, I find it hard to lay still, but it’s actually very rare that I get sick. It actually stresses me out to have to be sick, even just the thought of it, because I can’t imagine being stuck in my bed and recuperating. Who is going to look after all the kids? Who is going to take care of them? Who is going to make dinner? Some of them are getting old enough now that they can function, but they don’t function well. I have to come downstairs and spend three days cleaning after I have been sick for a day, so being sick really stresses me out.

What’s air travel like for you? And are you impacted by time difference?

I never get jet-lag and it annoys me when I travel and I see people asleep on the plane. I don’t sit still. In any relationship I’ve ever been in, they ask me to please sit still and watch the movie and I can’t, it’s like I have laundry to do or this other task to do, so being on a plane just drives me absolutely crazy. I feel like I need to get up and jog or something.

I’m happy to go on very long road trips — I’ve driven very, very far. I’ve taken my softball team to Louisiana, to Tennessee, to North Carolina. I’ve driven from Florida to New York a few times, and California. I usually take the kids and go straight through the night, so there’s about six to eight hours of everyone sleeping. I just keep on driving.

Does drinking impact your sleep?

I don’t get hangovers. If I overdo it and I get a headache, that’s saying a lot. Most people in their 40s are sick for a day and a half. If I drink too much, then I may go to bed at two and get up at six — maybe I get an extra hour’s sleep!

What happens when you take stimulants? I’d imagine things like a 5-Hour Energy or recreational uppers would have an extreme effect on you?

I have one cup of coffee a day, usually in the morning. I’m a Dunkin’ Donuts junkie — I love my iced coffee, so I usually have a medium whatever their specialty coffee of the month is and that’s my thing. I do think I need the caffeine.

What would you say is the best thing about being a short sleeper?

The best thing is that I have so many more hours in the day to get things accomplished. I still say I wish I had more hours in a day, and I have more hours than most people.

Do you get annoyed with people who count how much sleep they have had and complain about being tired?

Yes. Even when my kids sleep crazy amounts of hours I get annoyed. Teenagers can sleep probably for 12 hours straight, and I get so annoyed because I think they are wasting their lives. Why are you wasting your life sleeping? There are so many things that you could be doing. That’s how I see it. So, I don’t like them sleeping for longer than necessary because they are wasting their lives. That’s always been my thing. You have plenty of time to sleep when you die. You might as well embrace life.

This interview has been edited.