It is actually used in Biblical French, it is often the way that Christ is represented as
"The I AM." Veiled religious themes come out in Rimbaud's work here and there.

The Je-Est is a reference to the Luciferean Christ of mythology, the trickster, the clown Loki,
and in a way a bridge between west and near-east religious symbols. A Lucky-Fire is in
Islamic astrology Alligafir - or Venus. Venus is the "morning star" and Christ is known to have said "Yea Verily I am the Morning Star" The clown is in many languages a pun on Crown, and kingship - and is the quality of this character, this Clown - known to us as Bozo.

In the Turkish language Bozo means I Am.

Oddly the question asked of Lucifer in the Bible is "How art thou fallen O Star of the Morning?"

This revelation really changes the nature of the father-son relationship we are all so familiar with.

For an even more paranoid look into Je Est Un Autre - there is a much longer version of it
going around the Usenet, posted by MadCap - it is an Mp3 - sounds a bit like Durrell, it been put to music. Searching the lyrics got me here. There is a reference in that version saying bluntly that Shelley (and Byron) were murdered. Did Dr. Polidori fix them too stiffly?