I was listening to a song just now ("The Winner Is..." by Priscilla), and there's a line that goes "mais je n'en suis pas là" - I'm having trouble with this construction. I take it to mean "but I'm not there yet." Why is 'en' there? Is it referring to something previously mentioned? Here's the entire verse:
Mmmm je vois Johny Depp au bras
devant tous les photographes
mon meilleure sourir
le monde à genou
mais je n'en suis pas là
je travail ma voix
je me donne des coups et du temps pour aller haut
I'm able to understand the rest, but the en is throwing me off. I thought maybe there was such a verb as en être, but I don't think that's the case. And I thought en as an adverb replaces the preposition de or an adverb of quantity, etc.
If someone could clarify, it'd be greatly appreciated.

