The song is "New Best Friends" by the Swedish progressive metal band Wolverine.
Everyone talks about losing one's faith, yet no one talks about gaining it. So, you grow up, stop believing in The Tooth Fairy, Santa, Jebus, whatever imaginary friend your parents thought you should have to distract you from selling crack in the kindergarten. But where are the new imaginary friends? Nowhere to be found. So you have to settle being a Mr. Spock or a Batman cultist. Laaaaame. No heroes to believe in. So, naturally, people find their sanctuary in addictions. Drugs, soap operas, goat sodomy, you name it. Well, fuck that! When I grow up, I'm gonna be a hero. So, you better be nice to me - there will be a sidekick place opening soon. You know you want it. It comes with a shiny leotard.