calm and sensible
It is easy to really see this. But what does it mean to be level headed. A lot of it is the ability to keep their cool even when the world is falling apart. This is the real ability to be calm and sensible.
To keep their head clear even when they really should be panicking.
Just like how even in apocalypses we do need someone who is calm and able to face everything, so that some people can survive. And this is always positive. Being able to keep your cool in tough situations is a bonus.
Just like how leaders should not be panicking when their country is likely facing a crisis. Rather they need to be working on a viable solution, and that requires the ability to stay calm. And back to my original point, even as everything is truly falling apart.
How can this be important, this can be done in many many ways to show it. As well as used in many various ways to be spun, and very different.
As this is a trait, but they should not always be. People have limits and I do love to see a good struggle that even despite the immense amount of panicking, it is to really think about what just be done or the way out of such a solution.
Or the story is meant to crack them from the very beginning. Where it does it’s best to really make them think that it is going to get really really bad. Or they grow to eventually learn to become a little more so because the story demands for it.
Either way, this is a largely positive trait. And something we definitely want if they are making important decisions.