This quote suggests that the news we consume is often not new or enlightening to our innermost intelligence, our genius. Rather, it is a reiteration of what we already know or have heard before. The term "stalest repetition" implies that the news is not only redundant but also lacks freshness or novelty. It’s like consuming stale bread, it’s not harmful but it doesn’t add any value to our nourishment.

The concept of "our genius" could be interpreted as our innate wisdom, our intuition, or our ability to understand and discern. Thoreau suggests that the news we hear rarely challenges or expands this inherent wisdom. Instead, it often repeats the same themes, stories, and perspectives, leaving little room for fresh insights or innovative thoughts.

Applying this idea to today’s world, we might consider the vast amount of information we’re bombarded with daily through the internet, social media, and 24/7 news channels. Much of this information is repetitive, echoing the same viewpoints, and rarely offering new or enlightening perspectives. It’s easy to become complacent, accepting this repetition without questioning its value or seeking out fresh, challenging sources of information.

In terms of personal development, this quote could be a call to action. It urges us to seek out information and experiences that challenge our existing beliefs and expand our understanding, rather than settling for the stale repetition of familiar ideas. It suggests that we should strive to feed our "genius" with fresh insights, pushing ourselves to learn, grow, and develop in new and unexpected ways.

In essence, Thoreau’s quote is a reminder to not let our intellect and curiosity be dulled by the repetitive nature of the news and information we consume. Instead, we should seek out novelty, challenge, and growth, nurturing our inherent wisdom and understanding.