Reality could be described as a series of limitations on every living thing, the final boundary being death. In other words, we have only so much energy to expend before we tire; only so much in the way of food and resources available to us; our skills and capacities can go only so far - these things are inherently finite.
An animal lives within those limits: it does not try to fly higher or run faster or expend endless energy amassing food - that would be unsustainable and leave it vulnerable. Rather, an animal tries to make the most of what it has. A lion, for instance, instinctively practices an economy of motion and effort, and avoids wasting energy if possible. People who live without means, similarly, are acutely aware of their limits: forced to make the most of what they have, they are endlessly inventive. Necessity has a powerful effect on their creativity.
The problem faced by those of us who live in societies of abundance is that we lose a sense of limit. We are carefully shielded from death and can pass months, even years, without contemplating it. We imagine endless time at our disposal; we imagine endless energy to draw on, thinking we can get what we want simply by trying harder. We start to see everything as limitless – the goodwill of friends, the possibility of wealth and fame. A few more classes and books and we can extend our talents and skills to the point where we become different people. Technology can make anything achievable. Abundance makes us rich in dreams, for in dreams there are no limits. But it makes us poor in reality. It makes us soft and decadent, bored with what we have and in need of constant shocks and stimulation to remind us that we are alive.