Your Twitter friend sounds like Camus (that's a compliment). Camus asserts that there is no revelation, no hope that the universe can be revealed and understood. Not even with the scientific method. But that the act of existing itself (and trying to be happy) was in its own way a rebellion: that we are constantly choosing to create or adopt meaning. I think DeBord's exegesis for all of us is to be more conscious of the fact that we are adopting meaning all the time and perhaps try and create it consciously for ourselves instead. This is where your idea of "authentic" really resonates. You have good instincts.
