In this video, Nimoy talks about his early years as an actor. In 1956, he was working as a cab driver and Senator John F. Kennedy hired his services. At the 2:50 mark in the video, Nimoy spoke of this encounter. Here's a selection:
It was only about a 10-minute ride. He said, "What are you doing out here?"
I said, "I'm an actor."
So he said, "A lot of competition in your business."
I said, "Yeah."
He said, "Just like mine."
And we kicked it around a little bit, and then he said, "Just keep in mind, there's always room for one more good one."
That was very helpful.
via Sci Fi Wire