I looked at longevity in show business when I was about 13, and the people who seemed to have longevity were the ones who'd spent quite a bit of time learning about what they were doing before they made it. ↗
If I can make a career for myself after Potter, and it goes well, and is varied and with longevity, then that puts to bed the 'child actors argument'. ↗
You could argue that war is always an irrational act, and yet many states enter into military conflict out of rational calculation or national interest or the stability or longevity of their regime. ↗