It's easy to overlook the fact that a lot of Barney Fife's mannerisms predate The Andy Griffith Show. The character is so specific that it seems like all those traits could only exist in Mayberry. The truth, though, is far more interesting than any spur-of-the-moment decisions made on set.

Before The Andy Griffith Show, and even before No Time for Sergeants, Knotts refined his "nervous man" routine on the nightclub circuit. But how'd he come up with the act in the first place? Knotts' own Barney Fife and Other Characters I Have Known holds the answer in its pages.

"Most people don't believe me when I tell them the nervous character I did on The Steve Allen Show came to me in a dream, but it happens to be the truth," Knotts wrote. "A number of things were swimming around in me, of course, that led up to the dream."

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"Several months earlier, I had attended a luncheon during which one of the speakers was so nervous his hands were shaking visibly," Knotts continued. "He rattled the paper his notes were written on, and when he attempted a drink of water, he proceeded to spill it all over himself. It was a painful thing to watch, but at the same time, amusing."

Knotts was fascinated by the man's mannerisms from the get-go, but it wasn't until much later that he realized they could become the foundation for a full-fledged character.

"I wish I could say I suddenly thought to myself, 'What a great idea for a comedic character!' But alas, consciously, it went right over my head," Knotts wrote. "It was almost a year before it came to me, and even then it had to hit me over the head in a dream."

Knotts refined those mannerisms slowly, first in private and then onstage. Eventually, he developed the fully rounded, believable character of Deputy Barney Fife.

The rest is history.