Because adults have the perspective of being able to see long-term consequences for their actions in a way that children do not. Ice cream and pizza taste bett

Because adults have the perspective of being able to see long-term consequences for their actions in a way that children do not. Ice cream and pizza taste better than salad. If you let them, children will always pick them. Adults know that doing that all the time will actually make them sick and miserable, so they start making choices that are less pleasant in the immediate term because they want to optimize value for the long-term. Sure, some things are bullshit even in the long-term, but most of the things that seem "boring," like doing the laundry and paying the taxes and making the meal plans, are actually ordered toward optimizing happiness on a much larger scale than children have the life experience to see.