In a generation dominated by working class comedic vulgarity, his middle-class intelligence and sophistication was evident. Consequently he was not popular with his peers.
For me what saved him was his sense of self-deprecating irony. Here are three of his best jokes which - despite familiarity - are still pretty good.
"They laughed when I said I was going to be a comedian ... They're not laughing now."
"I can still enjoy sex at 74 - I live at 75, so it's no distance."
"I want to die like my father, peacefully in his sleep, not screaming and terrified like his passengers."
* ENTPs don't do (tertiary) Extraverted Feeling at all well: (Myers-Briggs personality theory).
If the connection between brain architecture and personality type interests you, take a look at this post. I've been reviewing recent results from the Human Connectome Project and my remarks back then seem to stand up pretty well.