It's Louis CK giving homage to George Carlin.
And it's freaking awesome.
The middle of the video is absolute spot-on advice for writers, as well as comedians (and, most likely, any creative professional). It's from about 4:10 to about 8:20. It's the truth and, really, is the only way to get better at a crazy creative job like this.
Throw out the old.
Speak the truth.
It's scary as hell, but do it anyway.