"When Albert Einstein was making the rounds of the speaker's circuit" joke

When Albert Einstein was making the rounds of the speaker's circuit,
he usually found himself eagerly longing to get back to his laboratory
work. One night as they were driving to yet another rubber-chicken
dinner, Einstein mentioned to his chauffeur (a man who somewhat
resembled Einstein in looks & manner) that he was tired of
speechmaking.
"I have and idea, boss," his chauffeur said. "I've heard you give this
speech so many times. I'll bet I could give it for you." Einstein
laughed loudly and said, "Why not? Let's do it!"
When they arrive at the dinner, Einstein donned the chauffeur's cap
and jacket and sat in the back of the room. The chauffeur gave a
beautiful rendition of Einstein's speech and even answered a few
questions expertly.
Then a supremely pompous professor ask an extremely esoteric question
about anti-matter formation, digressing here and there to let everyone
in the audience know that he was nobody's fool.
Without missing a beat, the chauffeur fixed the professor with a
steely stare and said, "Sir, the answer to that question is so simple
that I will let my chauffeur, who is sitting in the back, answer it
for me."