I found this recent overview of the theory of scarcity quite insightful. Time, knowledge, and money are all limited quantities, whose limitations must be managed.
And I would add two more scarcities:
Attention. The way to manage limited attention is to master the art of prioritization (as in time management), while training yourself to add a layer of focus to it. There’s a reason why mindfulness has become such a cliche in our always-on world of digital distraction.
Kindness. Intentional compassion is a kind of muscle that people must exercise. Build strength by managing reactivity, pausing, and being intentional about how what you do not only achieves your ends but affects others (directly in your path, and more systemically).