“This is my last press appearance,” Lin-Manuel Miranda told Seth Meyers December 20 upon arriving to Late Night With Seth Meyers. Miranda has been on a media tour to promote his feature film debut as Jack in Mary Poppins Returns, which opened in theatres nationwide December 19. The film stars Emily Blunt as the titular nanny, but also includes appearances by Meryl Streep, Angela Lansbury, and Dick Van Dyke.

“He's got the glint in his eye that he has had his entire career and they asked a lot of him. He has a tap solo on top of a desk,” says Miranda of Van Dyke.

“The week before we had contingency plans. 'If he can't get up on the desk, maybe you get under his leg. Emily, you're spotting.' If Dick Van Dyke falls he's falling either on Emily Blunt or Lin Miranda like, ‘We're not gonna let that guy—that is precious cargo you're not letting him touch the ground.’ We had all these plans in place and then he came in and he's human caffeine.”

Miranda himself is pretty non-stop. On December 21, he begins rehearsals for his return to the role of Alexander Hamilton for three weeks in Puerto Rico with the launch of the third tour of Hamilton.

“I think of my brain as a desktop with too many apps open. I just have to clean up the files. I never hit ‘empty trash’ at any point, they're all there,” he says.

Miranda also spoke about spending time with his family, including what it was like to have his son on set for Mary Poppins Returns and then show him the movie this past year: