Personality Change?

I'm not big on his movies, but his "Evening with Kevin Smith" talks from around 2001ish are genuinely hilarious. In those he came off as smart, witty, funny, and a great storyteller, particularly in the Prince and Superman/Tim Burton stories. There have been times recently where I've seen a link to a new interview with him and expected to see the funny guy with lots of cool anecdotes from those videos, but he seems like a totally different person now. He talks in a weird shouty voice and can't stay on the same subject for more than a few sentences. I know he started using pot heavily around the mid/late 2000's, but that shouldn't alter your personality that much unless he uses it so much that he's basically always baked.