BURBANK, Calif. — Jay Leno avoids waxing poetic about his 22-year “Tonight Show” run that draws to a close Thursday.

Instead, he relies on numbers to tell the story. Leno’s tenure is second only to Johnny Carson’s 30 years; “Tonight” was No. 1 among viewers when he took it over and will be when he hands it off to Jimmy Fallon; he’ll have taped more shows than any predecessor, Carson included, with the final and 4,610th one.

His dry assessment also may stem from a case of deja vu. After all, he lived through this before when he surrendered “Tonight” in 2009 to Conan O’Brien, only to reclaim it after NBC’s messy bobbling of the transition and O’Brien’s lackluster ratings.

But this time it’s different, Leno contends, offering another hard fact: The older generation has to make way for the younger one.

“It’s been a wonderful job, but this is the right time to leave,” said Leno. I’m at that age where I don’t really listen to the (current) music anymore. I’m not a big tweet guy. A 63-year-old guy reading Miley Cyrus’ tweets is a little creepy. Move on.”

He makes the argument with the precision of one of his reliable monologue jokes, just as he did when he claimed to understand NBC’s decision to evict him for O’Brien, even as he reamed the network on the air.

In 2012, “Tonight” laid off 20 staffers and Leno took a 10 percent pay cut. The show has averaged a 3.5 million nightly viewership in the past 12 months, which pales in comparison with the double-digit audiences it once claimed.

He insists his schedule won’t include another late-night show, which could only be what he calls “Tonight Light.”

“Tonight,” which launched in 1954, was shaped by original host Steve Allen and nurtured by successors Jack Paar and Carson.

Following them represented the pinnacle for comedians, and it was the role Leno coveted and won upon Carson’s 1992 retirement.

His first few months were marred by Leno’s longtime manager Helen Kushnick, who, as his first “Tonight” executive producer, was blamed for instigating nasty guest booking wars.

Worse was to come, when NBC’s “Tonight” host succession plan hatched in 2004 went awry. Leno, who stoically endured insults from Jimmy Kimmel and others who portrayed him as having stolen O’Brien’s job, says the past is past.

“Politically Incorrect” host Bill Maher, a regular “Tonight” guest, and Seth MacFarlane (“Family Guy,” ‘’Ted,”) serenaded Leno last week to the tune of “Thanks for the Memories,” the same one Bette Midler used to sweetly honor Carson.

“As a performer trying to make it in show business, and as a human being, you cannot do better than ask, ‘What would Jay do?’” Maher said.

Leno’s final show will feature Billy Crystal, his first “Tonight” guest, and Garth Brooks. Leno’s legacy — a word that makes him squirm — might include expanding the show’s opening monologue; a memorable mea culpa from Hugh Grant after he was arrested in 1995 with a prostitute; the first interview with a sitting president, Barack Obama, in 2009; and the “Jaywalking” fixture, which trips up people with simple questions.

Leno’s favorite Q&A is that those queried about how Mount Rushmore was formed often reply, “erosion.” His head-shaking reaction: “The wind and rain not only picked four presidents, it picked four of our greatest presidents!”

Leno cannot be called unsophisticated but he is determinedly unshow biz. He makes note of his modest New England upbringing, the high school friends he remains close to, his three-decade marriage to wife, Mavis, and the many “Tonight” staffers who remained loyal throughout his tenure.

Hollywood has been a place to get to tell jokes to a big audience, reap millions of dollars to be carefully saved and keep a safe distance from the circus.