"Because Jimmy Fallon lives on joy, and joy is not solitary. It’s why he’s not at his strongest in plain monologue delivery, and it’s why every single good bit he has is fundamentally a collaboration. Even something like "Thank You Notes," which seems to be just him reading cards, has morphed into a silly little dance he does with the keyboard player.
Fallon needs other people — that’s why it makes all the sense in the world that he closed this chapter in a sea of Muppets, sitting at a drum set in the back. And the balance between sincerity and goofery, which is the balance that his show has mastered almost from day one, is perfectly encapsulated in the fact that on the one hand, this is sort of warm and sweet, and on the other hand, Animal keeps popping out yelling “AAAAAND!” and Beaker sings harmony.
As I’ve said a bunch of times, the precise quality that could make Fallon irritating on Saturday Night Live — the inability not to laugh during sketches — was a glimpse at why his late-night show has been so utterly delightful. He gets so jazzed about things, and he’s so energized by the presence of other humans, that he has the poker face of a five-year-old. He laughs, and somebody else laughs, and then everybody laughs more. It’s not everybody’s thing, but boy, it’s been mine.”