This quote from Nassim Nicholas Taleb highlights a fundamental aspect of human psychology: the power of confidence and its role in persuasion and trust-building. It underscores that people are highly sensitive to signals of uncertainty or hesitation, which can quickly undermine credibility. This sensitivity parallels animal behavior, where being able to detect weakness or hesitation can have survival implications. In the realm of human interaction, the absence of diffidence or doubt projects authority and reliability, encouraging others to accept what is being said more readily.

The idea that "the trick is to be as smooth as possible in personal manners" emphasizes not just the content of what is communicated but also the style, delivery, and demeanor that accompany the message. This has implications in many areas such as leadership, negotiation, teaching, and everyday communication. Taleb's observation encourages individuals to manage not only their thoughts but their emotional and social presence to effectively convey ideas and foster trust.

This perspective can be both empowering and cautionary. While confidence is a powerful tool, it also suggests the thin line between genuine knowledge and mere performance. It invites reflection on how people respond not only to facts but to the confidence with which those facts are presented, highlighting the complexities of human belief systems shaped as much by perception as by truth.