Right away, Doug Moench and Bill Sienkiewicz let everyone know that this was a new kind of comic. More brutal, more animal than any you’d read before.
And on top of that, it had depth. There was no simple origin. Was he dead and brought back to life? Or was he just delusional? The creators trusted us, the readers, enough NOT TO TELL US. And they continued to keep it ambiguous forever.
I don’t think that had ever been done before in comics.