There are always young bands playing in their garages. A lot of punk rock is not going to be in the mainstream. It's below the radar. The beauty of it is that you're not supposed to always know. It's subterranean.

In this quote, Billie Joe Armstrong, the lead singer and guitarist of the punk rock band Green Day, reflects on the underground nature of punk rock music. He highlights that many young bands are constantly playing in their garages, which symbolizes the grassroots and DIY (do-it-yourself) culture of punk rock. Armstrong suggests that punk rock, in its purest form, often operates outside the mainstream, staying "below the radar" and deliberately resisting commercial success and widespread attention.

Armstrong’s comment about punk rock being “subterranean” refers to its underground, non-mainstream status. He appreciates the fact that much of punk rock remains hidden or obscure to the general public, which adds to its allure and authenticity. For him, the beauty of punk rock lies in its rejection of the mainstream and its embrace of a more raw and genuine expression of rebellion and creativity that isn’t meant to be universally understood or appreciated.

The phrase "you're not supposed to always know" reinforces Armstrong’s belief that part of punk rock’s appeal is its elusiveness. It’s not about making everyone understand or enjoy it; rather, it’s about creating something that resonates with those who truly connect with its message. Punk rock is meant to be a subculture, not a product to be consumed by the masses, and it thrives in the spaces where it can exist without the pressures of commercialization or mainstream approval.

Ultimately, Armstrong’s quote underscores the essence of punk rock as a form of self-expression that values authenticity and independence over popularity or fame. By staying beneath the radar, punk rock maintains its identity as an alternative and rebellious force, offering a space for those who don’t fit into mainstream culture to find their voice.