Fighting Sleep (Like Valentijn)

My baby nephew Valentijn, like everyone else, gets tired sometimes. And when he does, his grandparents will prepare him for bed. When they do, he's always fighting them, which is ridiculous. His tiredness is unmistakable, and when he finally gets put to bed, he falls asleep instantly. More ridiculous than that are the adults who, when they get tired, know they should get sleep but stay awake. I'm a very responsible adult, so for me, this isn't an issue at all. I've got a job, meaning I need to wake up in time, so I'll get in bed early enough to get some good sleep. But when I don't have my job the next day, I act just like my nephew, but unlike him, there's nobody to put me to bed except myself, so I stay awake, wasting so much of my precious free time for no good reason.