I suspected he was bipolar. I liked his work also, especially his dramatic roles.
I saw him on Carson one night, and he was almost levitating he was so up. He was so up he couldn’t turn it off, and in people like him there is a danger. If you’re on, you can get away with anything. If you lose it, you have to be perceptive enough to back off. That night he didn’t realize he’d lost it. It was very painful to watch for about ten minutes.
That’s the price you pay for being on the cutting edge of ad-lib comedy. You can be positively amazing one appearance, and positively flat the next.
I only saw one negative appearance on Carson, and he was pretty much universally appreciated.
I suspected as you did. I loved some of his dramatic roles also.