"I think it's your own choice if you turn from an angry young man to a bitter, old bastard"

In this quote, Billie Joe Armstrong is expressing his belief that it is ultimately approximately an individual to choose how they will age and progress as an individual. He utilizes the metaphor of an "angry young man" to represent someone who has plenty of passion and energy, however also prone to anger and frustration. As they get older, they have the option to either release that anger and become a more mature and content individual, or hold onto it and become bitter and resentful. Armstrong's usage of the word "bastard" adds a sense of cruelty and negativity to this prospective outcome. Overall, the quote suggests that our mindsets and actions in our youth can greatly impact our character in aging.