“My friends and I we've cracked the code”

Lorde – Royals Lyrics on LyricsMode
EXPLANATION
Society doesn't need to control you. You don't need money to be happy.
EXPLANATION
It implies drugs. In other words, it symbolically means that they've tried everything, that they can achieve things "royals" can not.
EXPLANATION
They've cracked the code and found the answer to how to be happy without money.