Probability is a beautiful mathematical theory in its own right, but it also is a theory that can be very widely applied.
Consequently, it is the goal of Undergraduate Probability to enable i.
Quantum mechanics and statistical mechanics are vitally informed by it, and its methods of analysis are frequently encountered in just about every field of knowledge or endeavor that uses quantitative methods: economics, business, psychology, sociology, meteorology, biology, chemistry---the list goes on.
Probability is a beautiful mathematical theory in its own right, but it also is a theory that can be very widely applied