The Tonight Show Starring Jimmy Fallon is the top late-night show among the 18- to 49-year-old set. He’s become known for the jokes and songs he does with his guests, which go viral on social media. Just this week, he and Jon Hamm recreated the iconic Creed song “With Arms Wide Open” on a Scottish Glen.

A year ago, he and Paul Rudd sang an ode to their favorite hat called “ Teenie Weenie Beanie .” But to be this endless source of hilarity, Fallon needs to stay well rested. So he takes sleep very seriously.

So seriously, in fact, that he’s helped design a sleepwear collection called P’Jimmies with the cult fashion brand Alex Mill that launches this week. It includes crisp cotton pajamas, eye masks, socks emblazoned with “Zzzzz” and an ingenious tote bag that transforms into a blanket, for easy, on-the-go napping. I sat down with Fallon to discuss his bedtime habits and the advice he has for getting the best possible sleep.

Your career involves you being very engaged and funny in the evening, from Saturday Night Live to The Tonight Show . Is it hard for you to wind down and get to sleep? | I think it’s tougher and tougher as I get older because I just come up with ideas throughout the whole night. They’re all insane, but some of them are really good.

Like, that’s how I came up with the idea of the song “ My Tight Pants .” [A song he sings with Matthew McConaughey.] But I hate the idea of not remembering them the next day.

So I always record my crazy .