Explore functional programming fundamentals in this GOTO Night 2012 conference talk by Erik Meijer. Delve into the core principles of functional programming, contrasting it with imperative approaches. Examine concepts like side effects, mutability, and lazy evaluation. Investigate the relationship between interface and implementation, and explore advanced topics such as monoids, category theory, and monads. Gain insights into the duality between functional and imperative programming paradigms, and understand how to acknowledge and manage effects in real-world applications. Learn from Meijer's expertise as he challenges conventional programming wisdom and presents a fresh perspective on software development.