Embark on a comprehensive 9-hour journey through Core Java, covering essential concepts from basic programming constructs to advanced topics like multithreading and lambda expressions. Learn about Java's history, popularity, and applications before diving into practical aspects such as variables, control statements, and object-oriented programming principles. Explore crucial elements like inheritance, abstract classes, and the collection framework, while also gaining insights into common programming errors. Delve into hashing, multitasking, and implement a multithreading project to solidify your understanding. Conclude by mastering lambda expressions and functional interfaces, equipping yourself with the skills needed to develop robust Java applications across various domains.