Knowledge by Green Day is a punk rock track that delves into themes of youthful uncertainty and the inevitable passage of time. The lyrics convey a sense of questioning and introspection, dealing with the challenges of growing up and the fear of the unknown. The song poignantly touches on the notion that while we may not have all the answers, the journey of learning and self-discovery is universal. It's an anthem that resonates with listeners facing the transition from adolescence to adulthood.