It is difficult, especially when young, to think about how out bodies are going to feel in the future so, we mistreat them and think that it will always recover as it has always done. It doesn't, and the less work done now, the more required later and it gets to a point where it isn't about feeling better, it is trying not to feel worse.
It is a problem. People get used to mistreating their bodies and then when getting older and body can't keep up with damage they blame life for not being healthy, but it's their choices really and lack of awareness.