Contra this, people's chronotypes change as they get older with people (on average) becoming more early birdish as they age. I think a lot of people struggle to recognise this and try to force themselves to continue to be night owls as they age, even though they would actually fare better if they started getting up early. I speak as someone who has gone from rarely going to bed before 2am when I was a yoof, to being someone who considers 6am to be a luxurious lie in. But I'm also dead on my feet by 10pm!