Understanding Lisp semantics is crucial because it unlocks the language’s unique power and flexibility. Since every Lisp expression is either an atom or a list (an S-expression), grasping these basics enables one to see how data and code interconvert seamlessly. This insight not only clarifies function application and variable binding but also lays the foundation for understanding advanced features like macros and metaprogramming. In essence, mastering Lisp semantics allows programmers to fully exploit its elegant and expressive design, which has influenced many modern programming paradigms.