"The trick is to make show-business money and still live a normal life," he says. "Show business is like Champagne ... it's nice every now and then, but if you drink it every day, you'll be an alcoholic."
Leno honed his observational comedy by performing stand-up throughout his Tonight Show reign. His signature style became extended monologues on the absurdity of everyday events. While he admits he hasn't changed his act over the years, he adapts the delivery as audiences evolve.
"People's attention spans have gotten smaller, so you learn that brevity is the essence of a joke," he says.
In an era of YouTube comedians, Leno revels in the connection from live audiences.
"I don't do HBO specials or DVDs because there's no shared experience," he says. "I would rather come to where you are."
Last year, Leno was awarded the prestigious Mark Twain Prize for American Humor, an honor he modestly downplays.
"Don't believe the bad stuff that is said about you and try not to believe too much of the good stuff," he advises. "I believe in low self-esteem. The only people with high self-esteem are criminals and actors."
Leno, who keeps his collection of 138 cars and 94 motorcycles in a private garage in Burbank, will host Jay Leno's Garage on CNBC next month, an expanded version of his Emmy-winning Web series.
It's fitting cars will steer Leno back into the limelight, since he first found inspiration to be an entertainer while he was working at a Rolls-Royce and Bentley dealership.
"The show is about my love affair with automobiles," he says. "I'm like Mia Farrow — if I see an abandoned car, I adopt it."