This quote by Mark Twain suggests that individuals who know less often make the most noise, or in other words, they are the most boastful or talkative. This could be because they are trying to compensate for their lack of knowledge or understanding by appearing confident or assertive. The second part of the quote suggests that these individuals often command higher salaries. This could be interpreted as a critique of society, where appearance and charisma can sometimes be valued more than actual knowledge or ability.

Applying this concept to the modern world, one could argue that it is particularly relevant in the era of social media and reality TV, where loud personalities often garner more attention and financial success than those who may be more knowledgeable but less assertive or charismatic. It’s also evident in various professional fields where individuals with strong presentation skills but less substantial knowledge or experience might climb the corporate ladder faster than their more knowledgeable counterparts.

In terms of personal development, this quote could serve as a reminder to focus on building genuine knowledge and skills, rather than relying solely on charisma or confidence. It also suggests the importance of humility and the ability to listen and learn from others, rather than always trying to be the loudest voice in the room. While confidence and assertiveness can be valuable traits, they should ideally be backed by real knowledge and understanding.