This quote suggests that just as only a small number of people have a significant impact on the world or on our lives, only a small number of books truly influence our thoughts, ideas, or beliefs. Most books, like most people, might provide momentary entertainment or distraction but do not leave a lasting impression or significantly alter our perspectives.

This concept can be likened to the Pareto Principle, or the 80/20 rule, which proposes that 80% of effects come from 20% of causes. In this context, it would mean that 80% of our intellectual growth and development comes from 20% of the books we read.

Applying this idea to today’s world, we might consider the overwhelming amount of information we are exposed to through various media. We consume vast amounts of content but only a small fraction of it truly influences us or contributes to our personal development.

In terms of personal development, this quote could be a reminder to be selective about what we read, just as we are selective about the people we let into our lives. Instead of trying to read as many books as possible, we might focus on finding those few books that truly resonate with us, challenge our thinking, expand our understanding, or inspire us to grow.

Moreover, this quote might also inspire us to strive to be among the small number who make a difference in the world or in the lives of others. Just as we seek books that offer depth, insight, and inspiration, we might aspire to offer these qualities to others through our own actions and interactions.