Get your lip-sync lyrics and musical impressions ready, because Jimmy Fallon is celebrating a big anniversary.

The giddy, giggly comedian has hosted NBC's "Tonight Show" for 10 years, if you can believe it. That's a decade of messy celebrity gag games, classroom instrument pop music and walk-on music by the legendary Roots crew.

Fallon inherited NBC's flagship late night institution after a period of upheaval resulting from the Conan O'Brien and Jay Leno mess (the short version: O'Brien didn't work at 11:30 p.m. and Leno left the show before he really wanted to) and managed to turn a stilted, rote talk show into something bubbly, youthful and fun. Since then, he's made YouTube magic, served Donald Trump a softball, created a lip-sync spinoff, quarantined at home, sung with celebrities, gone through a writers' strike and made it to his first big milestone.

This far into what might be a 20-plus-year journey, it's worth asking if his "Tonight" still has, you know, it. And what all the twists and turns of the past decade have done to Fallon's puppy-dog brand of comedy (you can catch up on the last decade in a clip-heavy two-hour 10th anniversary special Tuesday at 9 EDT/PDT on NBC). How many times can he throw water in someone's face and get laughs? Probably a lot more, as long as network TV survives.

When the former "Saturday Night Live" performer launched his version of "Tonight" in February 2014, he had already hosted NBC's "Late Night" for four years. where he established two things: that he was a playful, joyful guy with great games, and that he wasn't a very good interviewer. When he moved to "Tonight," the guests were more famous, the games got tamer and the videos went more viral. There was a period in the first few years of Fallon's "Tonight" where any game he played with a random celebrity would be racking up millions of views on YouTube by the next day.

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The games and softball interviews worked because Fallon is particularly talented at making other people look good. His boyish charm is part of a quiet personality that can easily fade into the background as a bold, brash celebrity takes center stage. He created an atmosphere of fun on his set that allowed others to relax, let loose and shine. Have a hidden talent for rapping Blackalicious lyrics, Daniel Radcliffe? Fallon will stand behind you while you jam with The Roots. Revisiting the show that unceremoniously dumped you 15 years ago, Conan O'Brien? Fallon will let you take over the interview to reminisce and crack wise. Have egg on your face? Get some literal egg on your face in a game of "Egg Russian Roulette."

It was all fun and games, until it wasn't. Fallon tries so hard to be uncontroversial that he can make serious missteps. In 2015 he was widely criticized for a puffy interview with then-presidential candidate Trump in which he literally fluffed Trump's hair. It hurt Fallon's reputation, but the interviews on "Tonight" are routinely skippable. He chuckles and flatters, oohs and ahs and never abandons safe topics for thorny ones. It seems like all good vibes in Studio 6B, no matter if in reality the vibes are very bad.

Following the Trump interview, Fallon had a creatively fallow period during the Republican's presidency when the host just could not rise to the cultural moment as his more political counterparts, CBS' Stephen Colbert, NBCs Seth Meyers and ABC's Jimmy Kimmel, did. He had Trump jokes, but they just weren't as sharp or funny as the others'. And in 2015, CBS launched James Corden's "Late Late Show," which quickly began nipping at Fallon's feel-good celebrity viral video heels (Corden exited in 2023).

But it was, surprisingly, the COVID-19 pandemic that brought life back into Fallon's "Tonight." The low-tech at-home version of the show during the early lockdown period used graphics done by his young children and jokes that captured the sense of disbelief we all felt. Fallon's "one of the people" persona worked because he was able to capture a universal feeling of absurdity. The aw-shucks tone of his show worked again.

In 2024, his videos aren't racking up tens of millions of views on the regular anymore. Scroll through his most popular YouTube uploads and you'll find barely any more recent than five years ago (although in the same span, TikTok has gained on YouTube as the video-sharing app of choice). There is a formulaic quality to a lot of the "Tonight" episodes that any long-running series can acquire. It feels dusty and a little dated when he breaks out the "Hashtags" segment for a social media platform now called X. He may look like a kid, but at 49 (turning 50 in September), Fallon isn't the young whippersnapper on the late night scene anymore (that would be CBS's Taylor Tomlinson hosting panel show "After Midnight" in Corden's old slot). He's one of a crowd of middle-aged guys in a suit trying to comment on TikTok videos. It's still pretty funny. It's just not as funny as that time he talked a screaming Kevin Hart onto a roller coaster.

As he settles into a comfortable groove 10 years in, it's hard not to miss some of the wild and weird stuff he used to do back on "Late Night" and the early days of "Tonight." Back when he gave audiences peanut butter sandwiches and tried to get them to talk while chewing, there was a lunacy to his giddiness that felt dangerous and funny. Of course weird humor infamously failed in the 11:30 time slot for O'Brien, so who could blame Fallon for playing it safe?

Still, network TV is receding from the spotlight in the age of streaming. Back in 2014 Netflix only had three original series. Now look at our streaming bundling universe. No one can predict what TV will look like 10 years from now. If Fallon or any late night host wants to go for longevity, they have to evolve.

We'll see if he can sing and dance his way into a new decade.